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RESIDENTIAL DESIGN GUIDEDecember 2009

4.1 Developments of 10 or More Dwellings4 Detailed Criteria

112428 Lockinge

Vale of White Horse Residential Design Guide December 2009 113

4.0 Detailed Criteria

The purpose of this section is to set out detailed criteria on how to plan and design the following types of residential development:

• Developments of 10 or more dwellings

• Developments of less than 10 dwellings

• Replacement dwellings

• Conversionofbuildingstoflats

• Developments in areas of lower density

• Residential extensions

• Conversion of agricultural buildings

• Conversion of chapels and churches

• Conversion of industrial buildings

• Refurbishment

This section does not repeat the principles set out inSection3.Insteadthissectionprovidesspecificguidance for individual types of development.

The topics within this section cover the same headings within Section 3. However, where specificadviceisrequiredforadevelopmenttypeit is set out with the use of detailed plans and specificguidance.

A pro-active approach should be adopted when planning for all sites, though this is especially important for larger sites where the potential range of issues is very broad. Early liaison with the council is recommended to determine the key issues which will need to be resolved. This may include the appropriate mix of dwellings, the amountofaffordablehousingrequired,meansofaccess,layout,andlocalissuessuchasflooding.

429 Cumnor Hill

430 Blewbury

431 Marcham


432 Abingdon

4.1 Developments of 10 or More Dwellings



The development is focused around the building rather than the road. However the road outline shows that a standard 4.8m road width could be applied throughout.

Traffic calming could be undertaken by narrowing the road orproviding integrated street parking - designed from the outset.

The majority of parking is located behind the building line either in garages to the rear or in parking courtyards which are contained by housing and have no public access.

The siting of buildings creates a legible layout where the route through is clear and easy to follow, with focal features such as buildings or landscaping at strategic points.

Site Layout

Section 3 above provides information on the general principles of a good site layout. This section provides a number of examples of how this can be successfully applied to large residential developments.

One of the most fundamental problems with many large residential developments constructed during the twentieth century is the dominance of the private car and the impact that has on the character of developments.

In a successful residential development the street hierarchy introduces a variety of spaces with differing levels of enclosure. This section illustrates some of the streets and spaces that can be incorporated into a site layout.

Image 433 below illustrates a typical village street found towards the centre of a settlement. In this example, a continuous built frontage is created by the buildings and the use of stone walls where there are gaps between the buildings. This creates a strong sense of enclosure, which helps to create a comfortable residential environment.

433 Typical Village Street Layout, based on examples in the Vale



Image 434 illustrates a typical block layout where amix of houses and flats are clusteredaround a central space, which is used for parking.Theperimeteroftheblock isdefinedby a continuous built frontage of houses and flats.

The development provides "eyes on the street" both within the block and looking outwards from the block.

The majority of parking is located within the largely visually enclosed courtyard, which reduces the visual dominance of the car on the street and on the buildings. Car parking is linked to individual units, with direct rear access to garages and spaces offered.

The siting of buildings and the approach to corners allows gardens to be provided for all houses and amenity space to be provided for all apartments.

Landscaping is introduced to the perimeter of the block to soften the built form.

434 Typical urban block layout, with internal courtyard parking



Image 435 illustrates a typical block layout where amixofhousesandflatsareclusteredaroundacentral open space. In contrast to the previous layout, the primary elevations of perimeter houses andflats focus inwardsonacentralpublicopenspace.

Dwellings overlook the central open space, providing "eyes on the street".

Frequentcornersandshortstraightsnaturallyslowstraffic,offering a safe pedestrian environment.

Landscaping is introduced within the courtyard to help create a more enclosed space and to protect the residential amenity of properties, which abut the street.

Linkages to other streets improves permeability.

435 Housing sited around open space, Wantage

436 Courtyard Housing overlooking public open space



Avenues can form an important part of an overall street hierarchy within a large residential development, but they need to be carefully designed to ensure that the car does not dominate.

Toensure that traffic speeds areminimised, thelength of avenues should normally be less than 200 metres.

Building heights and features such as tree planting can help enclose the space, thereby enhancing its appearance and helping to reduce trafficspeeds.

Existing mature trees can be utilised as a feature rather than seen as a constraint

Three to four storey housing and smaller street trees line either side of the street adding to the sense of enclosure

Onstreetparallelparkingprovidessufficientspaceinasustainableurban environment

Speeds are reduced by narrowing the street to a single carriageway on either side

437 Tree lined avenue, Abingdon

438 Avenue design based around existing mature trees



Built FormA significant problem within some largeresidential developments is the monotony of the built form. This can contrast with the historic streetscene where a greater variety of building types exist.

It is essential that residents have "pride of place' in their environment. Providing variety within the streetscene can help achieve this by creating a sense of identity. Using differing eaves and ridge heights, a variety of appropriate materials and colours, and a range of architectural features such as bay windows, dormer windows, chimneys, porches and boundary treatments can all help to achieve this.

Images 439 to 441 below illustrate how variety and interest can be achieved.

439 Well designed, uniform elevations create harmony

440 Different roof heights add variety

441 Careful, complementary selection of materials



Mix & Density

Elm Farm Close provides a broad mix of units, including one-bed flatsanddetachedfamilyhouses.

The site was developed at a density of 54dph. High density developments can be successfully delivered with good design and layout.

Design

Elm Farm Close incorporates a variety of building styles, which helps give the development a sense of identity.

Interest is added to the streetscene by incorporating variety in eaves and ridge heights and by introducing interesting design features such as dormer and bay windows. Doors are painted in bright primary colours, which are appropriate for the area.

Materials & Landscaping

This high density development is softened by landscaping. The three central trees provide a central focus for the development. Other planting to the front of properties provides an attractive setting for the dwellings.

The hard landscaping is also successful because of the use of appropriate pavers. Pavers can be attractive and low maintenance, and can also form part of a Sustainable Urban Drainage System (see 3.9).

Street Frontage

The frontage of Elm Farm Close onto Grove Road is less successful as the design of these elevations has less variety and fewer interesting features compared to the internal elevations. The introduction of an appropriately designed landscaping scheme could improve development’s appearance.

Case StudyElm Farm Close, Grove

442 Variety of images showing density, design and landscaping

Existing Potential

443 Existing Street Frontage 444 Potential landscaping improvements to street frontage


445 Marcham

4.2 Developments of Less than 10 Dwellings



Site Layout

Residential developments of less than 10 dwellings are frequently associated with ruralvillage locations, urban infill plots or villageexception sites for affordable housing. Each of these locations presents separate challenges for the designer, but the opportunity exists to respond to these challenges in a locally appropriate and environmentally sensitive way.

Section 3 provides information on the general principles of designing a good site layout. This section provides a number of examples of how this can be successfully applied to a variety of small residential developments.

Urban Infill

In urban locations, infill plots can be relativelycompact, which can challenge designers to deliver an attractive development that does not adversely affect the residential amenity of neighbouring properties. Courtyard housing can be used successfully on urban infill sites, particularly in areas of higher density.Courtyards provide good defensible space and can be designed to be formal or informal depending on the context.

Image 446 below illustrates an appropriate design for a highdensityurbaninfilldevelopment,whereafrontageproperty has been demolished. In this example, a courtyard approach is adopted. No dwellings face directly onto the backs of existing properties to ensure residential amenity is not harmed.

Original dwellings in street

New entrance and focal buildings

Parkinginlandscapedformalsquare

Rear courtyard parking

Mix of dwelling sizes and types from 1

bedroomflatsto4bedroomhouses

446 Typical higher density urban infill



Village Infill

In rural locations, infill plots can alter thecharacter of a village if not carefully designed. A higher density development (e.g. an informal mews or courtyard) can be integrated provided the design and layout of the new buildings respect the traditional streetscene and character of the village.

Image 448 below illustrates an appropriate design for a village infill. In this example, the existingbuilding line and form are maintained, but a contemporary element has been integrated into the traditional design.

By utilising the same plan form as surrounding dwellings a new terrace of four dwellings can be inserted in the space where there was an unimportant gap or, previously one or two dwellings may have stood.

Theelevationaltreatmentcanbemodernaslongasitdrawsinfluencefrom the surroundings

Building line maintained

Parking a combination of on street and rear courtyard with side street access

447 Successful village infill, Marcham

448 Example of village infill plot



Successful village infill, Marcham

Sub-division of Plots

The sub-division of residential plots to provide one or more additional dwellings represents one of the most common forms of new development in built-up areas.

The key factor for this type of development is that the site’s context should dictate the approach that is adopted for designing and laying out the new buildings.

Newbuildingsneedtofitcomfortablywithinthestreet, and there should be a positive relationship between the built form and the street.

449 Unsuccessful layout due to garage dominating frontage

450 Successful scheme, with contemporary design

451 Outbuildings are often converted to residential use and the plots are then subdivided accordingly

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Case StudyWheelwright Court, Buckland

Mix & Density

Wheelwright Court provides a medium density development on a sensitive site within Buckland Conservation Area.

The density of 18 dwellings per hectare is successful as it is consistent with the density of the existing cottages along Summerside Road, to the south. High densities can be successfully delivered with good design and layout.

Design

Wheelwright Court comprises a series of traditional vernacular cottages. The layout of the development with short terraces aroundaninformalmewsreflectsthecharacter of Buckland village.

A sense of individuality has been added to each dwelling using subtle variation in design, such as differing porch designs, feature windows and boundary walls.

Materials

The palette of materials utilised evokes the character of a traditional street in Buckland. The choice of natural stone for walls is entirely in keeping with neighbouring properties and the introduction of small brick sections on the elevations provides a visual break to the terraces and adds variety to the streetscene. Theuseofstonetilesontheroofsisalsoconsistentwiththelocalvernacular,howevertheotherroofingmaterial choice of clay tiles is less appropriate as it is not apparent in Buckland. The least successful material choice is the use of asphalt on the access road, a more appropriate material such as pavers would have enhanced the development.

Theoverallqualityofthedevelopmentissignificantlyenhancedthroughtheuseofqualitydetailsandfinishessuchastimberwindowsanddoorsandappropriatepaintcolourssuchassagegreenondoors.

Street Vista

The least successful aspect of Wheelwright Court is the arrangement of garages relative to dwellings and the impact of that arrangement on the vista available from Orchard Road. The choice of paint on garage doors is entirely inappropriate for the development and exaggerates their dominance of the streetscene. A more appropriate layout would have introduced a feature property at the end of the primary vista from Orchard Road. The Images below illustrate the potential opportunity for improvements.

452 Wheelwright Court site layout

453 Medium density, traditional design in a rural setting using local stone and stone slates

454 Existing vista and surfacing materials 455 Alternative vista and surfacing materials


452 Wheelwright Court site layout

456 Bothy Vineyard House, Frilford by David Wylie Associates

4.3 Replacement Dwellings



Site Layout

Proposals for the replacement of existing dwellings should be carefully considered in the context of the existing character of the area.

The most appropriate siting for a replacement dwelling is often on the footprint of the original building, particularly where the original building was planned and developed as part of a wider development.

The size of the replacement dwelling should be appropriate to the size of the site, and should carefully take into account its impact on the character of the area and the amenities of neighbouring properties. Excessive increases in size can result in a site appearing “over-developed”, which could potentially harm the character of the area.

It is also important to ensure the replacement building fits comfortably within the street andthere is a positive relationship between the built form and the street.

Built Form

Great care must be taken to ensure that the scale of the replacement dwelling is not unduly dominant. Reference should be taken from the local vernacular to determine the most appropriate proportions for the replacement dwelling. Modern room heights can put pressure on the need for higher eaves heights, however careful design techniques such as placing thefirst-floor ceiling above the level of the eavesbyusing coving can ensure that the building retains more traditional proportions. Similarly, traditional buildings usually have shallow plan depths which directly affects massing and ridge heights. The replacement of traditional dwellings, therefore, should reflect the local vernacular in terms ofbuilding depth.

457 Two storey replacement for bungalow - rear elevation

458 Example of contemporary replacement dwelling - plan

459 Example of replacement dwelling - front elevation

Original bungalow in white with enlargements proposed by new building in grey



Where accommodation requirements cannot bemet by maintaining traditional proportions, it may be more appropriate to introduce additions to the traditional plan form, such as bays and wings, to provide the additional accommodation, rather than increasing the proportions and bulk of the building. Such elements should be visually “subordinate” to the building’s form.

As stated above, the height of traditional buildings was often determined by the building’s depth. In some instances it may be acceptable for replacement buildings to be taller than the original. Taller buildings can be visually acceptable where the overall scale and proportion of building is in keeping with the character of the area – e.g. to provide a steeper roof pitch to reflectthetraditionalcharacterofthearea.

460 Replacement dwelling at Bothy Vineyard

461 Mixing contemporary design with the existing traditional form of the Bothy (below). Siting, openness and height were key to this sensitive site

462 The bothy has been restored as part of the dwellingBothy Vineyard House by David Wylie Associates - Design Award Winner 2006


463 East Hanney

4.4Conversion of Large Buildings to Flats



Design

The conversion of a building into self-contained flats is a common form of development inurban areas. Not all buildings are suitable for or capableofconversiontoflats–forexamplesmallterraced and semi-detached houses are less likely to be successful because of the limited space available. Older large houses and the upper floorsofbusinesspremisesaretypicallythemostappropriatepropertiesforconversiontoflats.

Where a property is being converted to flats,the development should, where possible, be contained within the existing building envelope. If extensions are necessary, for example to accommodate a lift or to meet building regulations, proposals need to be carefully designed – reference should be made to section 4.6 below on the appropriate design for residential extensions.

Character

Whenbuildingsarebeingconvertedtoflats,thepriority should be to retain the character and appearance of the original building. Stripping of any historic features should be avoided.

Where partitions are required to separate largerrooms or to introduce additional floors, theyshould not cut across windows. Similarly, any reductions in ceiling heights, if required forexample to accommodate air conditioning or additional pipework, should not be visible externally.

464 Conversion to flats can be undertaken sensitively

465 Modern elements should be harmonious

466 Rooflights should not be overly large or dominant

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x



Architectural Details

If dormers are required, careful considerationneeds to be given to their design, proportions, materials and position on the roof slope to ensure that they are appropriate to both the building and the character of the area.

An alternative means of providing light and ventilation to a roof space is to include roof lights. Wherever possible, roof lights should be included on rear elevations where they are less visible in the street scene. If the principle of roof lights is acceptable on a Listed Building or in a Conservation Area, “conservation” roof lights should be used.

The conversion of buildings to flats can lead tothe requirement for external pipework, flues,vents, meters, satellite dishes and aerials which candetractfromthequalityofthedevelopment.Wherever possible, service pipes should be grouped together and routed through existing features such as redundant chimneys. All such functional features should be kept off publicly visible elevations. Alternatively, features such as meters can be recessed behind purpose designed doors as an integral part of a building’s façade.

Satellite dishes and television aerials should be planned as part of residential conversions to provide a shared facility and so prevent the need for future retro-fitting by individual occupiers.Where practical, satellite dishes and television aerials should not be publicly visible – e.g. by placing them behind parapets or in roof valleys.

Access and ParkingThe conversion of buildings to flats can createsignificantproblemswithparkingandaccess. Itis government policy to reduce the dominance of the private car, and therefore in some locations reduced levels of parking may be appropriate, however a conversion to flats should notexacerbate on-street parking problems as a result a lack of on-site parking spaces. Where

467 Atriums can be effective at providing light

468 Dormers should be small and appropriately designed

469 Conservation rooflights suitable for historic buildings

470 Sun pipes let light into windowless rooms

471 External service can dominate

472 Letterboxes have to be carefully integrated

x



471

parking spaces are accommodated, they should not dominate the building, this can be achieved by either accommodating parking at the rear or by careful design, materials and landscaping. Parking at the rear of a building is likely to reduce the amount of usable amenity space available for residents.

Residential AmenityHabitable rooms and balconies should be positioned to prevent overlooking of adjoining properties. The provision of adequate acousticinsulation to reduce the transmission of sound between floors and adjoining properties is amatter covered by Building Regulations.

Wherever possible, flats should be providedwith adequate amenity space of 15 sq metresper bedroom. Balconies can contribute towards this amenity provision, provided they are of an adequatesizetoaccommodateatableandchairs.Preferably, they should not face north. Roof gardens offer a further solution for amenity space and can be attractive to residents. The inclusion of balconies or roof gardens should ensure that neighbouring properties are not overlooked.

Bin Storage and RecyclingSufficient covered external space shouldbe provided to house refuse and recycling containers. The structures need to be large enough to accommodate the bins without danger of overflow, and they should be convenientlylocated for collection without being unduly prominent in the street scene. Bin storage should be designed as an integral part of a scheme and built with compatible materials. Additional information on bin storage and recycling is provided in Section 3.4 above.

473 Dominance of private car at front of converted building

474 Balconies can provide amenity space for flats

475 Bin storage in an appropriately designed structure

x


476 Cumnor Hill

4.5Development in Lower Density Areas



Development in areas that are typically low density can be challenging, particularly in the context of the need to make best use of previously developed land, which includes gardens. This section examines how new development can be designed to make best use of a site and still be sympathetic to the character and appearance of the area.

Site Layout and Design

Lower density areas such as Cumnor Hill and Oxford Road in Abingdon are characterised by residential properties set in relatively large, often well landscaped grounds and this characteristic has made such areas attractive for redevelopment proposals. Government advice set out in PPS3 stresses the need for new development to make the best use of previously developed land. However, PPS3 makes it clear that there is no presumption that previously developed land is necessarily suitable for housing development. Development which is permitted must not detract from the character of the area. While PPS3 also says that more intensive development is not always appropriate, when well designed and built in the right location it can enhancethecharacterandqualityofanarea.

The established form and character of these low density areas should provide the context for the layout and design of any new development. The following matters need to be taken into account when designing developments in lower density areas.

Any new housing development, redevelopment or extension needs to understand the context provided by the architectural scale, modelling and language of the varying range of vernacular styles of these areas.

Any development should have a visual understanding of the residential vernacular tradition and style of the buildings and history of the area.

477 Characterised by the landscape rather than buildings

478 Typically single dwellings in large plots

479 Large plot sizes can create pressure for redevelopment



Extensions should be subservient to the existing building but in a manner that allows them to tie in with the style, form and design of the existing building.

Over intensive housing developments should be avoided. One way of increasing density without significantly increasing the number or size ofbuildings on a site is to incorporate a number of flatsintoabuildingwhichhastheappearanceofa large dwelling with one dominant front door.

Extensions, new developments or buildings should be set back from street/road frontages to respect the adjacent building lines and general character of the immediate area.

Side boundary separations of at least 2 to 5 metres (depending on the location) should be retainedatalllevels.Visualgapsthatreflectthegeneral character of the immediate area should be retained between buildings on adjacent plots.

All new buildings and extensions fronting a main road should face the street and have an active street frontage.

Buildings fronting main roads should be of an appropriate height and scale, with the potential for additional living space in the roof void. The scale and height of new developments should be in keeping with the general character of the area.

Exterior walls should generally be finished inmaterialsthatreflectthegeneralcharacteroftheimmediate area.

In traditional designs, roofs should normally be pitched, either gabled or hipped and consideration should be given to incorporation of front gables and gablets. Roofs should be tiled withmaterials that reflect the general characterof the immediate area, normally plain clay tiles or slates. Alternatively, in appropriate circumstances the opportunity can be taken to use innovative roofingmaterials suchascopper,zincor lead inhighqualitystand-alonebuildings.

480 A single building can be successful in lower density areas

481 The bulk of a large building can be reduced by simple forms and separate elements



Small gable or hipped roof front, rear and side facing dormer windows and eaves windows could be an acceptable way of providing additional living space without increasing the scale of buildings.

In traditional designs, windows should be wooden casement or sash style windows. Inclusion of bay or bow windows or other appropriate windows atgroundandfirstfloorlevelscouldhelpreflectthe general character of the immediate area.

Main entrance doors should be located on the front porches or under verandas. Front doors should be made into a feature through the use of surrounding detail and decoration.

Existing chimney stacks on larger properties should be retained.

Features such as Victorian lamp standards, street furniture, stone walls, fences, railings and pedestrian gates should be retained where possible.

Where possible new telecommunications and power lines should be located underground within development sites.

Thefrontboundaryofthesiteshouldbedefinedby either walls, timber fencing, railings and/or hedges to reflect the general character of theimmediate area.

Front gardens should be provided with lawns, tree planting, hedges and only small areas of hard surfacing either aggregate or paving. Where hard-surfacing for car parking in front gardens is necessary, it should be screened from view of the street by trees and hedge planting.

Retention of all trees and hedgerows, especially along property boundaries is vital. If trees and hedges do need to be removed, they should be replaced within the site.

Sufficient parking should be provided on site inaccordance with current standards. A limited quantity of parking could be provided to the

front of buildings and should be landscaped and designed in such a manner that it does not dominate the front garden or impact upon the amenity of neighbouring properties in accordance with current standards. Permeable surfacing should be used to limit any off-site surface water impact.

Anygaragingrequiredbydevelopmentsshouldeitherbeincorporatedintothebuildingsatthegroundfloorlevel or provided in detached buildings. Where there is a noticeable slope in the ground, it may be possible to cut a garage building into the slope with landscaping sweeping over the roof.

New entranceways and driveways shall be designed and constructed in accordance with Oxfordshire County Council's standards.

Access ways and driveways to developments shall be designed and landscaped to be informal and have a minimal impact. Driveways should be soft (not overly engineered with kerbs and hardsurfacing), well landscaped and boundary hedgerows and plantings should be retained and/or provided. Vision splays should be provided for vehicles and pedestrians in accordance withOxfordshireCountyCouncil'srequirements.

Sufficient refuse and recycling storage should beprovided. Discrete out of sight secure storage with easyaccesstotheroadfrontagewillberequired.TheCouncil will provide advice on the required size ofexternal refuse and recycling storage areas.

482 Care should be taken not to overdevelop the plot and ensure parking does not dominate



Case StudyPoet’s Corner, Cumnor Hill

Mix & Density

Poet’s Corner provides a high density development (46 dph) in a relatively low density area. The site, however, does not appear over-developed because of the design approach adopted. The building is similar in size to a large suburban house, which is appropriate to the context. In addition, the overall bulk of the building has been reduced by breaking up the elevations with set-backs and balconies.

Design

Poet’s Corner provides a contemporary design approach with three linked blocks arranged around a central stairwell. The window orientation offers natural surveillance of parking areas and circulation routes. The setbackoftheupperfloorensuresthatmaximum height can be achieved with minimum overlooking.

Materials & Landscaping

The palette of materials provides variety and interest to the elevations, and includes a mix of zinc, render, glass and timber cladding. The mix of materials also helps reduce the perceived bulk of the building.

The retention of much of the site’s original landscaping provides an attractive setting for the building and helps to frame key views into the site. The landscaping is relatively mature and so offers an effective screen between the site and adjoining roads. The site’s original landscaping has been supplemented with additional planting, including evergreen species such as laurel to provide screening in winter.

Sustainable Development

A positive aspect of the development is the inclusion of sustainable design features. In the parking area, a mix of permeable block paving and “Ecoblock” paving has been used. The development also incorporates rainwaterharvestingandphotovoltaiccellsontheflatareaoftheroof.

483 Poet's Corner site layout

484 High density and quality, contemporary design with a mix of materials

485 Grass block paving system allow green parking area 486 Contemporary rainwater harvesting system

4.6Residential Extensions


487 East Hanney



Extensions to dwellings can have a significant impact on the character and appearance of a dwelling itself and the street or area in which it is set. A well-designed extension can enhance the appearance and value of a property, whereas an unsympathetic extension can have a harmful impact, create problems for neighbouring residents, and affect the overall character of the area.

Contemporary approaches which provide high quality sustainable solutions, such as green roofs, can be successful in design terms.

This section examines the design approaches that should be adopted when extending a dwelling. It sets out the differing approaches that should be adopted when designing front and rear extensions, single storey and two storey additions, porches, garages and outbuildings.

Planning

Some smaller-scale extensions can constitute “permitted development” which means they do not need planning permission. The council’s Planning Service can advise on whether planning permission is required or alternatively, the Planning Portal website provides an interactive section.

Building Regulations approval may also be required for any extensions or alterations to a dwelling. Advice on Building Regulations can be provided by the council’s Building Control Service.

Design

Extensions should be in keeping with the shape, scale, proportions and character of the existing dwelling. They should be designed to be subordinate to the original dwelling, with a lower ridge line. Two storey flat roofed extensions will not usually be acceptable on a pitched roof dwelling. In the majority of cases, it is advisable to use

488 Simple, successful extension design

489 Small successful side extension

490 Successful contemporary extension



materials that match those of the existing dwelling. Roof tiles, facing bricks, stone, mortar colour, lintels, sills and other materials should usually be the same size, colour and texture as the existing. Buildings often have distinctive architectural features that contribute to their character, including ornate brickwork, plasterwork and arches. When extending a house, it is important to ensure the details of the extension complement those of the existing dwelling. Architectural features that are not in keeping with the design of the original dwelling and the area could look out of place and so should be avoided.

The position, size, proportion, height and style of new windows and doors and the ratio of solid wall to openings all help to define the character of a dwelling. It is important, therefore, that the extension continues the existing pattern and type of window and door openings.

Differing materials on an extension or a different design approach may result in a development appearing incongruous. Whilst, exceptionally, an extension may intentionally be designed to be contrasting, such an approach will need to be carefully justified and its success will rely on a high quality design

Landscaping

Mature trees and hedges can make an important contribution to the character of an area and, wherever possible, they should be retained.

When constructing an extension, all building work, including laying driveways and underground services, should be carefully planned and undertaken to ensure that existing trees and hedges are not harmed.

491 Successful materials matching

492 Successful details matching

493 Successful fenestration matching



40º Rule:

A two storey rear extension should not go beyond a line taken at 40º from the nearest point of the first floor window of any principal room in an adjoining property.

The potential loss of sunlight to neighbouring properties should be considered, even where developments comply with the above rule, as this can depend on orientation, layout, topography and position of adjoining properties.

495 40º Rule

Privacy and Amenity

The design of all extensions should take into account the impact on neighbouring properties in terms of overlooking, overshadowing and overdominance. Section 3.8 provides information on how to prevent harm to neighbouring properties.

In particular, two storey extensions should not encroach beyond a 40 degree line taken from the edge of the nearest first-floor window of a habitable room of a neighbouring property. Any side facing upper floor windows to habitable rooms (e.g. bedrooms) need to be carefully located and/or designed to ensure they do not cause overlooking problems for neighbouring properties.

494 Successful extension to maintain privacy

40º

No wind

ows

40º

40º40º



Front ExtensionsFront extensions can be challenging to design as they can detract from the continuity of the street scene and significantly change the appearance of a dwelling. Modest front extensions that reflect the character of the existing property are more likely to be acceptable. When located close to a neighbouring property, front extensions should not normally project more than 1.4 metres in front of the dwelling.

Front extensions are more likely to be acceptable where the building line is staggered or where the dwelling is set well back from the road. They should normally be designed with a pitched roof.

Porches & CanopiesPorches and canopies are not appropriate for all dwellings. For example, simple terraced properties can appear over-dominated by the addition of a porch. In such cases, an internal porch may be a more appropriate solution.

Porches and canopies should reflect the character of the original dwelling in terms of their scale, details and materials. When located close to a neighbouring property, they should not normally project more than 1.4 metres in front of the dwelling.

496 Small successful front extension

497 Range of porch designs

498 Alterations to frontage of terrace

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Side ExtensionsIn built-up areas, the gaps between dwellings can often be small. Cumulatively, these gaps can make an important contribution to the character of an area. Extending at two storeys to the side of a detached or semi-detached dwelling can result in development right up to the site boundary, resulting in an inappropriate “terracing effect”. The problem can be exacerbated where an extension has the same roofline as the original building and where a neighbouring property already lies on or close to the boundary.

To reduce such “terracing effect”, it is desirable to maintain a gap between the extension and the site boundary and for the extension to have a lower ridge height than the main building. The extent of the gap should be determined by the pattern of development in the area but, in general, it should not be less than 1 metre wide.

An alternative way of avoiding a terracing effect is to set the first floor element of the extension back from the front elevation – it should be set back at least one third of the depth of the dwelling.

Where the original building has a pitched roof, two storey extensions should be constructed with the same angle of pitch as the existing roof. Single storey side extensions will have a lesser impact on the appearance of a dwelling than two-storey extensions. It may be possible to increase the floor area of a single storey extension by ‘wrapping’ it around the rear of the property. A flat roof may be acceptable for a single storey extension, provided it is carefully designed – e.g. including a parapet wall with a coping stone on top.

The design of all side extensions should take into account the impact on neighbouring properties in terms of overlooking, overshadowing and overdominance. Section 3.8 above provides information on how to prevent harm to neighbouring properties.

499 Original unaltered dwelling

501 Single storey gabled side extension

502 Two storey extension, sub-ordinate to original dwelling

500 Lean-to side extension



Rear ExtensionsThe design of all rear extensions should take into account the impact on neighbouring properties in terms of overlooking, overshadowing and overdominance. Advice on how to design two storey extensions to avoid having a harmful impact on neighbours is provided in Section 3.8. A general rule is that any two-storey element should not encroach beyond a 40 degree line taken from the edge of the nearest first-floor window of a habitable room of a neighbouring property. The length of single storey rear extensions should not normally exceed 6 metres on a detached dwelling, 4 metres on a semi-detached dwelling, and 3 metres on a terraced dwelling.

Extending terraced and semi-detached dwellings represents the most significant challenge in terms of potential loss of residential amenity due to the close proximity of neighbouring properties. Problems can be mitigated by limiting the scale of the proposed extension and applying the 40 degree rule. An alternative solution is for neighbours of adjoining properties to work together to extend both dwellings concurrently.

Where the original building has a pitched roof, two storey extensions should be constructed with the same angle of pitch as the existing roof.

Single storey rear extensions and conservatories often do not need planning permission as they can be built under “permitted development” rights. Please consult the council’s Planning Service for further advice.

503 Two storey extension, shared with neighbour

504 Single storey gabled extension

505 Two-storey gabled extension

506 Double "M" shaped gable

507 1.5 storey catslide extension



Loft Conversions & Roof ExtensionsA loft conversion is a space efficient means of extending the amount of living accommodation in a dwelling. The most significant challenge associated with loft extensions is how to introduce roof lights and/or dormers that are appropriate to the character of the original building.

Dormer windows should be designed as features principally to provide light and ventilation. They should be small and should sit appropriately in the roof-slope, well above the eaves line, well below the ridge line and set in from the gable ends. Two or three smaller dormers are often more successful than a single large dormer. Flat roof or pitched roof dormers can be successfully integrated into the majority of building designs. However, the choice of design should be informed by the character and appearance of the existing dwelling and the surrounding area.

An alternative means of providing light and ventilation to a loft conversion is by introducing roof lights or windows into gable walls. Where possible, roof lights should be included on rear elevations where they are less likely to be visible in the street scene. In sensitive locations such as on listed buildings and in conservation areas, ‘conservation type’ roof lights should be used.

Self Contained Annexes

Residential annexes generally provide self-contained accommodation and offer a degree of separation from the main dwelling. However, they need to be linked to the main dwelling, both physically and in terms of the inter-dependence of the use of the annex and the main dwelling.

The design of residential annexes should follow the same principles as other residential extensions. In addition, they should share the front door and entrance hall of the main dwelling, and they should be designed to be capable of being incorporated into the main dwelling at a later date.

508 Successful and unsuccessful loft conversion

Original dwelling

x

x

509 Successful and unsuccessful dormers and roof lights

510 Example of a residential annex



Density & Plot CoverageThe extension to the Old Bakehouse, Kingston Bagpuize is a relatively large extension, with a frontage width similar to the width of the original building.

The extension, however, is successful because the site is large enough to accommodate the development and it has been well designed with the use of good quality materials.

DesignThe design of the extension to the Old Bakehouse is strongly influenced by the original house. The extension is subordinate to the original house as the front elevation is set back and the ridge line is lower. This ensures the extension remains subordinate and reduces the bulk of the overall building.

A successful feature of the extension is the simple arrangement of the windows and doors .

Landscaping & Materials The development is framed by mature landscaping, which has a softening effect and channels views into the site towards the attractive front elevation.

Additional landscaping has been introduced in front of the original building and the new extension. The parking and circulation area has been laid with gravel, which is appropriate to the context of the site and offers the benefit of sustainable drainage.

The palette of materials is appropriate to both the existing dwelling and to Kingston Bagpuize. The materials include coursed limestone, red/orange brick and buff brick window surrounds, and slate on the roof. A successful feature is the replicated ornate brickwork on the window and door arches.

A less successful element is the use of UPVC double glazed windows on both the original property and the new extension. On the front elevation, a more appropriate solution would have been to retain and refurbish the original timber windows and incorporate new timber windows of a similar design.

Case StudyOld Bakehouse, Kingston Bagpuize

511 Space is maintained

512 Successful design

513 Successful materials

514 Site layout plan

515 UPVC Windows 516 Alternative timber windows


4.7Conversions of Agricultural Buildings

517 Steventon



The conversion of traditional agricultural buildings such as barns, stables and cartsheds is the most common form of conversion in the Vale.

Continuation of the original agricultural use is usually most appropriate to preserve the character and appearance of such buildings. However, if a building is no longer needed or suitable for modern agricultural purposes, its disuse can result in the building falling into disrepair. Conversion to an alternative use is a successful way of securing the future of such traditional agricultural buildings.

This section examines the design approaches that should be adopted when converting agricultural buildings to residential use. It should be noted, however, that residential conversions are not always the most appropriate solution, particularly where the building is listed or is situated in an isolated location in the open countryside.

Structural IntegrityMany agricultural buildings will have been unused for extended periods of time or they may not have been well maintained – consequently, their structure may have suffered. The structural integrity of a building will be a critical factor in determining whether it is capable of conversion without substantial rebuilding or extension. If substantial rebuilding or extension is required, it is unlikely that planning permission will be granted as the proposed works would no longer constitute a conversion.

A structural report will need to be submitted with any planning application to demonstrate that the building is capable of conversion without substantial rebuilding or extension.

518 Example of unconverted agricultural building

519 Example of unconverted agricultural building

520 Buildings must be structurally sound for conversion



Architectural & Historic CharacteristicsThe importance of an agricultural building to the history, character and appearance of an area can be assessed with reference to its age, design, form, materials used, roof structure and the presence of any architectural detailing.

The form of traditional agricultural buildings typically comprises substantial stone or brick walls, uninterrupted roof slopes, long ridge lines, few openings apart from the large waggon doors, substantial timber roof structures, and large internal spaces. Architectural detailing may include patterned brickwork, dentil courses, buttresses, arrow slits and gable parapets. These features are essential to the building’s character and, therefore, need to be retained as part of the proposed conversion.

Agricultural buildings typically have an informal farmyard or open field setting. The proposed conversion should respect the building’s setting, either as part of a group of traditional buildings or as part of the surrounding landscape.

Design Approach

The primary objective of all conversions must be to retain the character and appearance of the original building. This may require compromises in terms of the residential layout and the provision of natural light into all habitable rooms.

The introduction of conspicuous domestic features such as chimneys, satellite dishes, aerials, porches and additional window or door openings tend to be out of character with the original building and, wherever possible, such features should be avoided. Natural light can be provided by introducing glass roof tiles, glass insertions into honeycomb brickwork and slit windows. Existing openings in elevations can be used for windows or doors, and to “borrow” light into the more central parts of the building. A simple window design is usually most appropriate.

521 Existing hay doors contribute to the barn character

522 Large doors contribute to the barn character

523 Traditional courtyard arrangement



Internal walls should be retained and the introduction of additional walls kept to a minimum. Timber roof trusses should be retained and not cut or removed to provide head height at first floor level.

Large extensions or ancillary buildings are not usually appropriate for conversions. Such elements can dominate the original building and so detract from its character. Wherever possible, existing ancillary buildings such as cart-sheds should be used as garaging to avoid the need for new buildings.

Landscaping and boundary treatments need careful attention and should be designed to be as simple as possible. Hard and soft landscaping should be kept informal, and walls, fences, kerbing and any other urban features should be avoided where they would harm the building’s agricultural character or farmyard setting.

524 Successful retention of existing openings

525 Domestic style porch alters the barn character

526 Glass roof tiles and small high level windows

x



Site Layout

Tithe Barn House has a traditional agricultural layout comprised of the primary barn with ancillary outbuildings sited at right angles. The layout provides good opportunities for privacy and shelter, as well as enabling domestic features such as cars and garden paraphernalia to be concealed from the streetscene.

Design

The design of Tithe Barn House includes the introduction of very few domestic features into the elevation facing the street. The windows that have been introduced on the street elevation are high level and informal and, as such, do not detract from the agricultural character of the building. In addition, it is clear that efforts have been made to ensure the new external materials used match the building’s original materials as closely as possible.

However, two windows have been introduced on the side (east) elevation. These windows are visible from the street and are domestic in scale and design. These windows dilute the overall quality of the conversion. A further domestic feature is the chimney that is visible on the western end of the main barn. This is an incongruous feature on a traditional agricultural building. In addition, the rear elevations have more fenestration and a more domestic appearance which, although not visible in the street scene, detract from the agricultural character of the building.

Case StudyTithe Barn House, Cumnor

527 Courtyard layout

528 Street elevation

529 Side elevation

530 Site layout

531 Existing courtyard elevations 532 Alternative courtyard elevations


533 Ashbury

4.8Conversions of Chapels,Churches & Schools



The conversion of chapels, schools and churches is less common in the Vale than barn conversions. Similar to barn conversions, the design challenges associated with the conversion of these buildings often relate to the creation of room and floor divisions in buildings which originally comprised large internal spaces.

Structural Integrity

Although structural integrity is less likely to present a problem compared to barn conversions, the issue still needs to be addressed. Where there are any uncertainties about the structural integrity of the building or where additional loads are being placed on the building’s structure, a structural report will be required.

Architectural & Historic CharacteristicsThe defining characteristics of chapels, schools and churches are often similar, comprising formal proportions and a simple rectangular footprint, tall sash windows, brick or stone arches, uninterrupted roof slopes, long ridge lines, and large internal spaces, sometimes with mezzanine floors. Architectural detailing may include stained glass windows, ornate timberwork and plasterwork on walls and ceilings, and ecclesiastical memorials. These features are essential to the building’s character and, therefore, need to be retained as part of the proposed conversion.

Chapels, schools and churches are typically located in central village locations. The buildings rarely include much external space, which can present a challenge for residential conversion in terms of providing amenity space and minimising any overlooking of neighbouring dwellings.

534 Successful retention of feature windows

535 Successful retention of original porch

536 Successful retention of original porch



Design Approach

The primary objective of all conversions is to retain the character and appearance of the original building. This may require compromises in terms of the residential layout and the provision of natural light into all habitable rooms.

The introduction of conspicuous domestic features such as satellite dishes, aerials, and dormer windows tend to be out of character with the original building and, wherever possible, such features should be avoided. If additional light is required, it may be appropriate to introduce glass roof tiles or appropriately designed rooflights (i.e. conservation rooflights which are designed to be flush with the roof plane ).

The internal wall divisions should be retained and the introduction of additional walls or floors should be kept to a minimum.

Existing window openings and window detailing, such as stained glass, should be retained and refurbished. Where additional floors are introduced, they should not cut across tall windows in such a way as to be visible from outside the building. Large extensions or ancillary buildings are not usually appropriate for conversions. Such elements can dominate the original building and so detract from its character.

Any existing ecclesiastical fixtures and fittings should be retained wherever possible, and the inclusion of additional detailing which would detract from the character of the building should be avoided.

Landscaping and boundary treatments should be designed to be as simple as possible.

537 Internal floor division is visible through window

538 Unsuccessful removal of original entrance

539 Small rooflight allows light to upper floor

x

x


540 Woolstone

4.9Conversions of Commercial Buildings



A variety of commercial buildings have played a significant role in the history of the Vale, including mills, shops, pubs and breweries. The design challenges associated with the conversion of these buildings can vary significantly and can be particularly difficult for buildings such as mills and breweries which have large internal spaces and tall ceiling heights.

Architectural & Historic CharacteristicsWhilst pubs and shops usually have a domestic scale and design, industrial buildings such as mills and breweries are usually much larger, with a more formal architectural composition. The defining characteristics of these industrial buildings include formal proportions usually in a rectangular plan, and large windows (i.e. plate glass in iron frames with top-hinged openings, small pane timber sash windows or Crittall Windows).

Roof forms tend to be relatively simple, but where buildings have large floor plans, the space may have been spanned by a multi-ridged roof with a central light atrium. Architectural detailing may include arched brick window and door openings, ornate brickwork and iron fittings on external elevations, and internal iron rafters and structural braces. These features are part of the history and character of the building and, therefore, should be retained as part of the conversion.

541 Retained industrial feature

542 Retained ornate brickwork

543 Retained industrial feature



Design ApproachThe primary objective of all conversions is to retain the character and appearance of the original building. Consequently, conversion schemes need to be carefully designed.

The introduction of uncharacteristic features such as satellite dishes, aerials, and dormer windows should be avoided. If additional light is required it may be appropriate to introduce glass roof tiles or appropriately designed rooflights.

The internal walls should be retained and the introduction of additional walls or floors should be kept to a minimum. Existing window openings and detailing should be retained. Where additional floors or mezzanines are introduced, they should not be visible through windows.

Large extensions or ancillary buildings are not usually appropriate for conversions. Such elements can dominate the original building and so detract from its character. Wherever possible, existing ancillary buildings such as storage sheds should be used as garaging to avoid the need for new buildings.

Existing commercial or industrial fixtures and fittings should be retained wherever possible. Original features such as internal metalwork can make a positive contribution to the final scheme. The introduction of additional detailing, which would detract from the character of the building should be avoided.

Landscaping and boundary treatments need careful attention and should be designed to be as simple as possible. Walls and fences should be avoided where they would harm the building’s character or setting.

Paint colours and finishes should be chosen to reflect the character and appearance of the building.

544 Industrial character retained in conversion

545 Atrium used to allow light to upper floors

546 Original features retained, existing openings retained

547 Simple landscaping softens industrial buildings


548 Steventon

4.10 Refurbishment


4.10 Refurbishment

The Vale is fortunate to have a rich architectural heritage, with over 2,000 listed buildings (ranging from large country houses to modest cottages), 8 Historic Parks and Gardens and 53 Conservation Areas. Collectively, these contribute to the distinctiveness of the District and represent a valuable architectural, historical and economic resource.

The architectural heritage of the Vale should be safeguarded for future generations to enjoy. This does not mean, however, that all buildings need to be preserved unchanged. Instead, their sympathetic refurbishment, alteration and adaptation will be encouraged to prevent possible disuse and decay.

Where a building is listed, consent will be required for any external or internal alterations which affect its character. Whilst all proposals are considered on their merits, certain works to listed buildings are unlikely to be acceptable in principle. Examples include installing UPVC windows, re-pointing walls in cement-rich mortars, removing original features such as fireplaces and staircases, painting exteriors in inappropriate colours, installing satellite dishes or other domestic paraphernalia on prominent elevations, and adding poorly designed extensions.

This section examines the design approaches that should be adopted when refurbishing buildings.

Structural IntegrityAs with conversions, building restorations and renovations can encounter structural problems. Where there is any uncertainty about the impact proposed works would have on the structural integrity of a building, a structural report will need to be prepared.

Design ApproachThe primary objective of all refurbishments is to retain the character and appearance of the original building. Consequently, conversion schemes need to be carefully designed. The

549 Refurbishment of thatched dwelling

550 Refurbishment of dwelling

551 Windows should be refurbished where possible


4.10 Refurbishment

approach, however, may differ depending on the design and location of the building. For example, the post-war building boom resulted in many houses being built which are of neither good traditional or modern design. If refurbishment is being considered, then the opportunity should be taken to improve the appearance of such dwellings.

In more historic buildings, it is important to retain any features which contribute to the architectural character of the building. In the past, architectural features have often been removed and replaced in the mistaken belief that they cannot be repaired. Stripping the historic fabric should always be avoided and, wherever possible, architectural features should be retained and repaired

A key consideration in all refurbishments, but particularly for refurbishments of historic buildings, is the compatibility of modern building methods and materials. For example, historic buildings with solid wall construction are not compatible with modern cavity wall construction, as solid walls are designed to absorb moisture whereas cavity walls are designed to keep moisture out. Similarly, it is rarely successful to retrofit buildings with damp proof courses and concrete floors as these can restrict moisture movement and prematurely decay the building’s fabric.

The choice of materials should be compatible with the building – for example, on historic buildings, lime mortar should be used on solid wall construction instead of modern cement as it allows the wall to breath. External paints should also be breathable, which will be compatible with the building and will help prevent peeling and cracking.

Where a refurbishment proposal includes an extension, reference should be made to the advice set out in section 4.6. The design of any extension should be appropriate to the scale, layout and design of the original building. In some circumstances, it may be more appropriate to design a light-weight modern extension rather than copy the style of the original building. Wherever possible, inappropriate modern additions should be removed as part of any refurbishment.

552 Refurbishment of post war buildings is encouraged

553 Historically and locally appropriate stone roof tiles

554 Extension appropriate in scale and design



4.10 Refurbishment Case Study

2 Church Villas, Blewbury

555 Design award

556 Landscape retained

557 Original building

558 Appropriate paint

559 Site layout

560 Elevation

Density & Plot Coverage

Although relatively large, the extension to Church Villas is successful because the site is large enough to accommodate the development and it has been well designed with the use of good quality materials.

Design

The design of the extension to Church Villas is strongly influenced by the original house, but with a contemporary twist. The extension is subordinate to the original house and does not detract from the character or form of the original building.

The development was considered so successful that it was awarded a Deisgn Award by the Council in 1991.

Landscaping & Materials

The dwelling is framed by mature landscaping, which helps soften the development and visually encloses to the site.

The palette of materials used on the extension is appropriate to the original dwelling, and the use of timber detailing on the light well is particularly successful. The use of clay tiles also successfully reflects the original roof tiles.

Paint

The original and new fenestration has been painted in a locally appropriate heritage colour. The choice of colour complements the orange/red brickwork and significantly enhances the appearance of the building.

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