Non-Domestic Building Regulations Part L2A, L2B : 2010 Section 6 – Scotland.

The route to net zero carbon buildings Customer Day 22nd September 2010.

“To reduce the effect of Global Warming

by limiting greenhouse gas emission

from buildings, transport and industry.”

UK Government target - 34% reduction in CO2 by 2020

- 80% reduction by 2050

The reason for change to Regulations

Trias Energetica Principle

The Energy Performance of Buildings Directive requires

all EU countries to enhance their building regulations

and to introduce energy certification schemes for

buildings.

The Influence of the EPBD

England & Wales / Scotland objectives

Reduce CO2 emissions as part of longer

term objective to meet UK and European

Climate Change Agreements

Help facilitate future energy supply

security

Improve compliance

A key step on the road to zero carbon

buildings

Resulting Regulations - England / Wales

ADL2 (2002)

Elemental method

ADL2 (2006)

Target CO2 Emission Rate (TER)

SBEM National Calculation tool

Air Tightness Testing

ADL2 (2010)

New version of SBEM

25% CO2 improvement

2002 2013

ADL2 (2013)

Further improvements

Renewables essential?

Devolved Wales Regulations

2006 2010

Looking further ahead – to Zero Carbon

ADL2 (2016) Further improvements

All new schools proposed to be zero carbon

All new non domestic

buildings to be zero

carbon

2020

Central Government depts.

(and wider public sector) will

have cut their greenhouse gas

emissions by 30% since

1999/00

2018 2019 2016

All new public sector (non domestic) to be zero carbon

The shape of things to come?

The shape of things to come?

Image: William McDonough & Partners.

Real life example project

Gazeley Blue Planet, Chatterley Valley,

- Outstanding BREEAM rating

- UKs first carbon positive logistics development

ADL2A – New buildings other than dwellings

England & Wales

Five Criteria For Compliance

1. Achieving acceptable building CO2 emission rate (BER) 25% overall improvement compared to 2006 regs.

2. Limits on design flexibility. Maximum allowable building fabric U-values, maximum air leakage and standards for building services are mandatory.

3. Limiting solar gain in summer – to prevent overheating

4. Building performance consistent with BER. Prove that actual building meets design

5. Providing information for building log book.

Criteria 1. Achieving acceptable building CO2 emission rate (BER)

The National Calculation Method

The NCM has been devised to carry out this complex task. It

comprises a calculation engine called the „Simplified Building

Energy Model‟ (SBEM) operated within a user interface called

iSBEM

This 2010 software is now freely available - either downloadable

from the BRE website or on CD-ROM.

How are the 2010 Calculations to be carried out?

Whole Building Energy Modelling

Calculations take account of the building

type / occupancy / location / orientation

and include assessment of :--

Thermal characteristics of the

envelope

Insulation

Windows

Thermal bridges

Air infiltration

Heating installation

Air-conditioning & ventilation

Fixed lighting (including controls)

Day lighting

Renewables, CHP, district H&C,

The National Calculation Methodology - SBEM

Achieving 25% CO2 reduction.

The 2010 Notional building is intended to yield the required 25%

reduction in CO2 on aggregate when applied to projected mix of

new buildings

Non-domestic building type % new build CO2 reduction Target

Shallow plan (heated only) 1 22%

Shallow plan (Air conditioned) 1 40%

Deep plan (Air conditioned) 40 26%

Warehouse (inc Factories) 33 34%

Hotel 6 16%

School 4 27%

Retail 12 21%

Supermarket 2 26%

How do I comply?

The SBEM Notional

Building Specification

helps!

Notional Building Specification

Notional Building 2010

– the starting point for design

The specification of the Notional building

is based on delivering equal marginal abatement

costs across all components

The Notional Building Fabric

Notional building

2006 2010

Wall: 0.35 W/m²K

(60mm)

Roof: 0.25 W/m²K

(80-90mm)

Glazing: 2.20 W/m²K

Air permeability of

10 m³/hour at 50Pa

Wall: 0.26 W/m²K

(80-85mm)

Roof: 0.18 W/m²K

(110-120mm)

Glazing: 1.80 W/m²K

Air permeability of

5 m³/hour at 50Pa

Panel thickness increase circa 35%

Calculation

Tool

Standard

Activity

Schedule

CO2

Actual

Actual

Fabric & plant

Compliance Methodology

Building

geometry Is A≤T? OK N

Revise design

Y

Actual

building

CO2

Notional 2010

standards

Fabric & plant

Notional

building

Target=Notional

The Impact of Renewables.

Low & Zero Carbon Systems

Technologies include –

– Solar PV

– Solar thermal hot water

– Solar hot air collectors

– Biomass boilers

– Wind

– Biofuel

– Geothermal heat

All can contribute to reducing carbon

dioxide emissions from buildings.

Criteria 2. Limits on design flexibility

Backstops

• No change to building fabric backstops.

• Building services and lighting backstops are

mostly improved.

Back Stop U-Values

– Backstop U-values / Air infiltration remain same as 2006 – Table 4.

Roof – 0.25

Wall – 0.35

Windows – 2.2

Air Infiltration 10 max

„In general, achievement of the TER is likely to require

better fabric performance than set out in Table 4‟ – Quote from ADL2A 2010 section 4.30

Criteria 3. Limiting Solar Gain in summer

Limiting solar gains

• Any zone that is either occupied or mechanically cooled is

subject to the new solar gain limit check.

• Solar gain limit check is done by SBEM or

• CIBSE TM37 and BB101 give ways of assessing solar

overheating.

Criteria 4. Building Performance Consistent with BER – Quality of Construction

The calculated additional heat loss through a junction thermal bridge is known as a Ψ(psi) value.

Ψ values represent the rate of additional heat loss through that bridge over and above the rate of heat loss through the main envelope elements.

Values for linear thermal bridges have to be put into SBEM.

Thermal Bridging

Typical Construction Detail showing f & psi values

Construction Details

Accredited Construction Details

Accredited Construction Details Schemes

(with QA on site) are being introduced.

25% (or 0.02 W/m.K which ever is greater)

penalty for using manufacturers details using

„competent person‟ or

50% penalty for generic details (IP 1/06)

Currently there are no schemes in existence

One proposed scheme estimates cost of £1600

/ detail!!

Measurement of air infiltration (leakage) is a

mandatory aspect of compliance:-

Can only be done after building completion

Building must achieve a minimum of 10m3/h/m2

@50Pa.

Final BER calculation with actual, tested air infiltration

must be compliant.

Research is underway to assess relationship between

building type / size and air infiltration achieved in

practice.

Air Leakage

Criteria 5. Providing Information

Log Book

All Buildings designed to 2010

Regulations will require a Log Book

Purpose:-

To help owners / occupant to

operate and maintain the building in

an energy efficient way

Additional Noteworthy Changes.

CO2 emission rate calculations along with

specifications to be given to Building Control

BEFORE start of building work.

New guidance on shell and core developments

– SBEM calculation required with „assumed building

services‟.

– When building is fitted out the a new submission

to Building Control is required to prove

compliance.

Achieving cost effective compliance

The Notional Building – England & Wales.

The specification of the Notional building in based on delivering equal

marginal abatement costs across all components

– Roof U-values 0.18

– Wall U-Values 0.26

The Notional Building is the starting point for design.

However – going beyond simple building regulation compliance recent

research by Aecom has shown that even lower U-values are cost

effective for the following building types –

Warehouses

Factories

Hospitals

Schools

Hotels

U-Values : 0.16 roofs / 0.20 walls.

ADL2B – Existing buildings other than dwellings

England & Wales

Existing Building Stock

Non-domestic buildings in the UK account for 18% of

all CO2 emissions.

Refurbishment of existing stock is key to achieving

long term CO2 reduction targets.

Research by Caleb Management Systems has

evaluated the opportunities related to non-domestic

building refurbishment.

Overview of L2B

• New mandatory requirements for improved

building fabric performance

• New mandatory requirements for improved

building services and lighting

• Requirements for consequential improvements

retained

• No significant changes to the compliance

process.

Refurbishment – New Thermal Elements

New Thermal Envelope Requirements

2006 2010

Wall: 0.35 W/m²K

(60mm)

Roof: 0.25 W/m²K

(80-90mm)

Glazing: 2.20 W/m²K

Wall: 0.28 W/m²K

(75-80mm)

Roof*: 0.18 W/m²K

(110-120mm)

Glazing: 1.80 W/m²K

Mandatory panel thickness increase 25-35% * Flat roof or roof with integral insulation

Refurbishment – Upgraded Existing Thermal Elements

Upgrading Retained Thermal Envelope

2006 2010

Wall: 0.35 W/m²K

(60mm)

Roof: 0.25 W/m²K

(80-90mm)

Glazing: 2.20 W/m²K

Wall: 0.30 W/m²K

(70mm)

Roof: 0.18/0.2 W/m²K*

(100-120mm)

Glazing: 1.80 W/m²K

* Subject to factors such as load bearing capacity

of frame etc

Refurbishment – Upgraded Existing Thermal Elements

Complex rules including –

– Upgrade of whole area required if area to be

renovated is >50% surface area of the element OR

>25% of whole building envelope.

– Upgrading to the best standard is required if

achievement of the U-value requirements is not

„technically and functionally feasible or would not

achieve payback of 15 years‟.

Consequential Improvements

Additional work is required for buildings over 1000m2 floor area

– Extensions

– Initial provision of fixed building services

– Increase in capacity of fixed building service

Spend on consequential improvements must be at least 10% of

the value of the „principle works‟.

– Upgrade of existing fabric is a possible option assuming it is

„technically, functionally and economically feasible‟ and has

payback less than 15 years.

Transitional arrangements permit work

to be completed to 2006 Regulations if :

1) Work was started on site by 1st October 2010

2) Initial planning notice was submitted before 1st October

2010 and work starts before 1st October 2011

Starts on site after 1st October 2011 must comply with

the 2010 regulations

Transitional Period

Section 6 – Scotland Non- Domestic

Overview.

Special Scotland only version of SBEM in 2010.

30% CO2 reduction for all building types compared to

current requirements (2006).

New rules for shell and core developments

New rules for non-domestic refurbishment.

Scotland – New Build fabric backstops

Fabric Backstops

2006 2010

Wall: 0.30 W/m²K

(60-70mm)

Roof: 0.25 W/m²K

(80-90mm)

Glazing: 2.20 W/m²K

Wall: 0.27 W/m²K

(75-80mm)

Roof: 0.20 W/m²K

(100-110mm)

Glazing: 1.80 W/m²K

30% CO2 reduction compared to existing regs.

Mandatory thickness increase circa 25%.

Shell Buildings

Mandatory Fabric Backstops –

–Walls 0.23

–Roofs 0.15

–Rooflights 1.6

– Air infiltration 7

Shell certified under building warrant.

Scotland – Extensions / Unheated Building Upgrade

Extensions to existing buildings & conversion of

unheated buildings.

Fabric maximum U-values –

– Walls 0.25

– Roofs 0.15

– Rooflights 1.6

– However, trade off IS allowed provided area

weighted U-value conforms to the above

requirements.

Scotland – Refurbishment of Heated Buildings.

Insulated envelope should be assessed and upgraded as follows

-

Fabric „maximum‟ values –

– Walls 0.30

– Roofs 0.25

– Rooflights 1.6

However, these values are not mandatory and can be reviewed

on a case by case basis.

No requirement for consequential improvements in Scotland!

Summary

Implementation Timetable

England & Wales - 1st October 2010

Scotland - 1st October 2010

Summary U-Values - Roofs

Roof U-values of 0.15 to 0.20 will become mandatory

in some circumstances

– 0.15 max mandatory in Scotland for shell

buildings,

– 0.15 max in Scotland for refurb of unheated

buildings and Extensions (trade off allowed).

– 0.18 max mandatory for refurb in England / Wales

– 0.20 max mandatory for new build in Scotland

0.18 Notional Roof U-value for new build in England &

Wales

Summary U-Value - Walls

Wall U-Values of 0.23 to 0.30 are mandatory in the

following situations –

– 0.28 max mandatory for refurb (replacement)

– 0.30 max mandatory for refurb (upgrade)

– 0.27 max mandatory for all walls in Scotland

– 0.23 max mandatory for shell buildings Scotland

– 0.25 max mandatory for extensions / conversion

Scotland

Wall Notional U-values 0.26 in England & Wales.

Summary

2010 is a significant step on the road to zero carbon buildings

The 2010 changes are significant and will drive the building fabric

and building services performance to their limits.

Buildings in 2010 can comply without renewables but renewables

will help compliance and give a financial return.

It makes sense to think about the future now and think about going

beyond the requirements of the 2010 revision to „future proof‟ the

building.

2013 – Separate regulations for England, Wales & Scotland.

RIBA Approved CPD is available.

Compliance isn‟t getting any easier!!

One final thought……

Teamwork!