Combining Technology and Tradition

Traditional timber frames are currently enjoying a resurgence in popularity. With recent decades displaying

a trend for modern, manmade materials in the construction of buildings, we are now witnessing a counter

movement in design tastes that favours more ‘traditional’ materials such as wood and natural stone.

Traditional, however, does not mean low-tech – in fact, quite the opposite.

A timber frame building is a complexstructure and even designs forrelatively small-scale projects requirethe highest levels of accuracy andmeticulous attention to detail –mistakes are extremely costly. In aunique approach to the issue, aGloucestershire company is makinguse of ArchiCAD’s 3D modellingcapabilities to pre-empt problems onsite and identify misalignments ormissing elements during quotationand planning stages.

With such specific requirements,though, the company needed asoftware product flexible enough toaccommodate a bespoke add-on thatit knew would be necessary to enabledetails of its specialised operations to

be incorporated into the 3D modelscreated. Using ArchiCAD this wassmoothly achieved and the net resulthas been more efficient projectdelivery, significant time saving, adramatic reduction in errors, plusextremely satisfied customers and aconsiderable improvement to bottomline profits.

The Missing Link

The Oak Frame Carpentry Companyemploys two full-time designers toundertake the planning and design ofa range of projects, in both traditionaland contemporary styles – from small-scale conservatories and domesticextensions through to houses, bridgesand larger structures, such as barnconversions or public buildings (likeChapelfield Retail Development inNorwich, an arcade structure 8m talland over 60m long incorporatingmore than 60 tonnes of oak).

Whilst the firm does not have theprofessional indemnity required toprovide legally endorsed architecturalplans, architects undertaking thedesign work will often bow to thecompany’s in-depth knowledge of thisbuilding technique. As a result, agreat deal of in-house time and efforthas always been put into developingdetailed design recommendations forthe jointing of every timber frame – acrucial aspect of the finished

GraphisoftCustomer Story

A timber frame building is a complex structure,requiring the highest levels of accuracy

structure, taking into account thelocation, constraints of the materialand angles required.

The main preoccupation with suchcomplex jointing is the avoidance oferrors which are costly in terms oftime, money and materials. Tim Potts,Director of the Oak Frame CarpentryCompany, explains further: “To produce a timber framedstructure, individual pieces of timberhave to be jointed at one or bothends so that they fit together into anoverall frame – if any of these joints isnot entirely accurate, the frame will beimpossible to piece together. None ofthe wood we use is uniform so no lineis absolutely straight, requiringprecise calculation to ensure a perfectmatch when the sections (which weprefabricate off-site) arrive on-site.

“Sections are laid together in theirentirety as a flat plan before arrivingon site to check that nothing ismissing, but they can be huge andinvolve any number of complex joints.It’s really critical that, when it comesto fitting these components togetherin three dimensions, they matchperfectly (something which cannot bedone until on site as dismantling isnot easy and risks damage to joints).

“Before the move to 3D design, we

had to rely on human skill andexperience, but mistakes did happen,and once a piece of timber has beenjointed it’s irreplaceable. If there is anerror, either the whole timber has tobe re-sourced, and accuratelyreplaced into the lay-up (costly interms of materials and labour) or ithas to be patched up, taking upvaluable man-hours – and these costsmust be absorbed in our profitmargins.”

With the design and specificationbeing so involved and complex, thepricing for each project – establishedon an individual joint-by-joint basis forevery job – is also highly timeconsuming. And all this input isundertaken before the company caneven guarantee it has been awardedthe job.

The Perfect fit

In an effort to minimise time input intoquotations and maximise the accuracyof designs produced, Potts researchedthe merits of CAD systems anddecided this was the only way toachieve the company’s goals.

Graphisoft’s ArchiCAD software wasselected for its multi-level functioning(adjustments made in one aspect ofthe design will be passed through toall files, correcting 3D, 2D, spreadsheetsetc) and file sharing capabilities.

For his specialist requirements Pottsidentified the need for a bespokeadd-on to ArchiCAD. This wasdeveloped by Bristol based softwaredesign company and ArchiCADdistributor, Encina, and has becomeknown as Framewright.

Potts remarks, “It was clear from thestart that ArchiCAD was trulydesigned with architects in mind, ithas an intrinsically logical format andworks in a way that is sympathetic tothe architect’s own thought process.

GraphisoftCustomer Story

Summary

Timber frame structures require the highest levels of accuracy andmeticulous attention to detail. The Oak Frame Carpentry Companybenefits from ArchiCAD because it:

• eliminates human error in design and cutting

• reduces the man hours and risks involved in making changes

• offers high levels of visualisation for both clients and the workforce

• defines the materials, cutting requirements and labour for each job

• enables all contractors to share a common model eliminating errors

• reduces costs in the workshop and avoids rework costs on-site

• raises the perceived value of products and the level of professionalism

• significantly increases profits by cost control and realistic pricing

Individual components must fit togetherperfectly in three dimensions

As an added benefit to speeding upquotation and design stages we couldsee that it had the potential to raisethe perceived value of our processand products and minimise on-siteerrors. However, being such aspecialist niche sector of the market,we needed ArchiCAD to perform anumber of very specific tasks thatother disciplines may never requirebefore we could achieve this.Fortunately, for us, ArchiCAD’sflexibility enabled Framewright to beincorporated easily”

Framewright was developed solely toaddress the Oak Frame CarpentryCompany’s needs. Specific featuresincluded allowances for calculationson curved timber, custom profiles ofany section of the design, and theability to rotate in 3D space. Withsome framing components obviouslyhaving irregular shapes that cannotbe described parametrically, theFramewright system will convert a user-defined shape – drawn using any of thestandard ArchiCAD tools for drawingpolygons – into a framing object.

Furthermore, every object (stored in aGDL [Geometric Description Language]library containing a parametricdescription of each generic type oftimber object) holds detailedinformation about the dimensions,hours to create each joint, extralength in the timber to allow for thecorrect cut for the joint specified,weight, volume etc. This is critical toimproving the efficiency of the overallprocess since it means that, once thejointing designs are completed,scheduling plans, estimates, materialrequirements and labour allocationsare all automatically generated.

Not only does this save considerabletime and man hours, but also themodel created can be used toactually show customers (and

subcontractors) what their finishedproduct will look like. Potts comments:“This is an impressive benefit, and onewhich often helps to ‘seal the deal’.Moreover, the perceived value thisadds and the level of professionalismit gives, allows us to charge apremium for our work. It, therefore,supports our profit margins from twoaspects – helping us to charge a pricethat genuinely reflects the value of thework we do and avoiding costsincurred by errors that mightotherwise inevitably occur duringcutting or, more costly still, on site.”

Working withArchiCAD/Framewright

The timber sections are usually laidout carefully, before being taken tosite and erected, to check all theparts are there. Joints within thesesections can be checked in theworkshop , however, joints betweeneach flat section cannot, butnonetheless must match to themillimetre. The sections can beenormous and, in practice, there is noway of checking them before thestructure is put together on site. So,creating an accurate library of jointsand requirements within the softwarehas offered a new way of working, away of virtually building the designand checking the plan is correct.

“The Framewright add-on took some18 months to evolve, but has morethan made back our outlay over thetwo and a half years we have beenusing it. It is quite straightforward tooperate, though more in-depthprojects can make use of morecomplex features.

“Actually starting to use the softwareproperly did take some time, though,”he continues. “Since we not only hadto learn to use the technology beingprovided, but also change oursystems (and even mind-sets) to

GraphisoftCustomer Story

Virtual reality: from ArchiCAD to installation

GraphisoftCustomer Story

accommodate the new approach. It

meant adjusting the way we think

about our designs, the way we quote

and charge for them, and the way we

present to clients.”

The ArchiCAD software is designed

with an intelligent cursor that easily

identifies halfway and divide and

measure points on the fly., or selects

sections for viewing elevations or 3D

cut-aways. It also utilises GDL

objects: scale sensitive 2D and 3D

views that include data attributes that

when incorporated into a model also

include parametric information (such

as weight, joint type, hours required to

create the object, excess material

needed). These GDL objects are

readily reusable as each is able to

record many attributes but requires

little disk space to store. Therefore

developing libraries with tens or

hundreds of objects is convenient and

economic. Each piece of timber is

saved as a GDL object and then used

within the design to ensure the

required precision is achieved.

Because the software stores standardobjects and data rather than definedjoint profiles, it provides a verypowerful tool which allows theCarpentry Company to experimentwith different designs and plan bills ofmaterials and programmesaccordingly.

“If I select a standard piece of lineartimber from the GDL library and wantto add a particular type of joint ateither end, the software immediatelyupdates the impact of this decision onthe overall design,” explains Potts.“The areas affected might include theamount of labour I should allocate tocarry out the work, or the quantity ofextra materials I will need to order.

“We would not usually see our designin 3D until it is actually put together,this literally gives us anotherdimension! It is not so much thatproblems are identified, it is more thatthey simply do not occur – except incases where the error is due toelements outside of our calculations,such as an issue with the site.”

Spreadsheets, 2D plans, materialrequirements and schedulingdocuments are all produced directlyfrom the details included within theArchiCAD model. This significantlyreduces set-up time for each project,ultimately enabling the company tohandle a greater number of projects,and, with the added perceived value,allowing a significant premium to becharged.

“Being able to actually show clientswhat to expect is a further benefit,”says Potts. “With 2D plans it is oftendifficult for a customer to visualisehow the finished product will look,using this software we can show allaspects of the design, including how itmight fit within its context, andchanges can be made quickly andeasily. Of course, it also helps the

“What we ended up with was anextremely happy customer who will now recommend us – an idealsituation that builds our reputationand allows us to charge morerealistically for the work we do.”

Tim Potts, Director of the Oak FrameCarpentry Company

Spreadsheets, 2D plans, material requirementsand scheduling documents are all produceddirectly from the ArchiCAD model

Schedules

Plans

Sections/Elevations

GraphisoftCustomer Story

carpenters to have a 3D illustration torefer to when the joints are being cutand the frame assembled in theworkshop. Customers are usually veryimpressed by this and tend to see thecompany as high-tech, professionaland reliable as a result.”

In addition, the file exchangecapabilities (of which Graphisoft is along time pioneer) have changed theway the company can manage a job.Site information can be importedfrom an existing CAD file – althoughinitial CAD information is generally notto a high enough standard and oftenhas to be worked on before itachieves the accuracy required – thedesign is then worked up and, finally,exported back to the architect. Thisavoids the need for repetitive draftingand, again, saves considerable time.

A case in joint

Indeed, the integration of the newsoftware into the working practice hasfacilitated a broad range ofimprovements as particular projectshave arisen.

For Britannia House – a 16th Centurylisted building in Gloucestershire –restoration was a complex concernsince special consent was requiredfrom the Council in order to progress.Using the 3D modelling to visualiseplans to the Council (and to producethe cutting list and workshopdrawings) ensured that approval wasgiven quickly and the work wascompleted accurately.

For technically demanding projectsthe software has come into its own.As part of a project in Lacock,Wiltshire, the company was asked todesign a single storey timber frame togo above a masonry ground floor.

The building was constructed using aseries of “Cruck” A-frames (where twohalves of a curved tree are used to

form an A-shaped structure) with thehorizontal members running betweenthem supporting the roof and definingthe walls. Clearly the precision of thejoint profiles themselves wasparamount but it was also necessaryto ensure that the timber frame wouldbe compatible (both aesthetically andpractically) with the masonry floor andthe roof purlins, which would beconstructed separately. After anaccurate survey of the site masonry, itwas discovered that these cruckframes would have to be positionedirregularly, out of parallel with eachother and out of square with the walls.

Details from the survey were importedinto the software and then the exactpositional adjustments of the cruckframes were made in the model,allowing the resulting angles betweenthe horizontal roof purlins in the planeof the roof, and the cruck bladesthemselves to be calculated. Thesehighly complex and irregular angleswere then simply taken from themodel and the workshop drawingswere produced defining each joint.

“Of course, in the workshop thecarpenters had no way of testingwhether the odd cuts they were beingasked to make would create thedesired result,” explains Potts. “Butwhen the frame was fully erected ontothe masonry on site the purlin line wasstraight and true, with no furtheradjustments required. It was certainlya great moment for us to see thisproject come together with such ease,particularly when one considers thecomplexities it would have posedwithout the modelling technology.”

“Being able to visualise plans hasproved invaluable in many ways,actually,” continues Potts. “Not just interms of technical planning but also toensure we really do achieve what theclient wants. Because makingchanges using the ArchiCAD softwareis so straightforward, with adjustments

ArchiCAD helps the company to be seen as high-tech,professional and reliable

GraphisoftCustomer Story

Adjustments are made automatically at every levelwhen something is changed

made automatically at every level

when something is changed, it means

we can actually sit with a client and

run through ‘what if’ scenarios.”

For example, in a recent project at

Waldron Farm, involving a classic

add-on conservatory (with open

central truss and glazing fitted direct

to the oak) the 3D model allowed

detailed client consultation over exact

proportions, detailing of the oak work,

and the overall form of the building.

“What we ended up with was an

extremely happy customer who will

now recommend us – an ideal

situation that builds our reputation

and allows us to charge more

realistically for the work we do.”

And the file-sharing capabilities further

enhance the efficiency and accuracy

of our work. This is particularly well

illustrated by a large residential project

attached to a historic farm building.

The 3D model was initially created

from detailed architects’ drawings.

Using this, the best method of

construction for the new frame was

identified, with the various disciplines

having input. The single information

model created in ArchiCAD was then

used by all parties involved in the

project to store and manage

information, rather than each of them

creating their own plans separately as

is commonly the case. Not only did

this avoid considerable redrafting time

for each party, since they were

effectively able simply to update one-

another’s drawings, but it also meant

that various discrepancies were

discovered which could have led to

expensive errors on site.

Conclusion

The benefits for the Oak FrameCarpentry Company of using theArchiCAD 3D modelling software andGDL objects are clear to see. Thealmost complete elimination of humanerror and the time savings in terms ofman hours could never be matchedby manual systems.

Customers also benefit, however,thanks to the high level of visualisationoffered by these 3D models. Manyclients – particularly on domesticprojects – find it difficult to visualisewhat their finished structure will looklike so it’s important to be able to givethem an impression in a way they canunderstand.

Tim concludes: “The software enablesthe entire project to be managedmore accurately with no omissionsand with no costly re-work. Itprovides us not only with the price ofthe frame, but also the cutting list forthe sawmill, the workshop timeallocation, volumetric data for deliveryand, of course, a fully rendered 3Dmodel for visualisation. Almost everyaspect of the work flow in thiscompany has been improved.”

ArchiCAD and the Framewright add-on are now vital business tools for theOak Frame Carpentry Company. Theinitial effort spent integrating thesystems into the running of thebusiness has been more thanrewarded by the money saved byincreased operating efficiencies andthe extra margin generated throughthe delight of satisfied customers .

ArchiCAD comes with a range ofspecial functions to address the needsof similar niche markets, and is alsohighly flexible in enabling thedevelopment of individual solutions tobe integrated as add-ons.

Graphisoft UK LtdFrankland House, Frankland Road, Blagrove, Swindon SN5 8YF. United Kingdom

Tel: +44 (0) 1793 492277 Fax: +44 (0) 1793 492288 www.graphisoft.co.uk info@graphisoft.co.uk

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