Tel 01934 838624
BUILDING REGULATIONS
PART L 2006 Extension, Alteration, and Conversion of Existing Buildings
L1B L2B COMPLIANCE
SBEM, SAP, EPC
Domestic and Non-domestic extensions, alterations and conversions
by Stephen Kinsella CEng MIEE FCIBSE
FOR OWNERS, ARCHITECTS, DEVELOPERS, BUILDERS, SURVEYORS
UK REGULATIONS for CARBON DIOXIDE EMISSION from energy use in ALTERED BUILDINGS - CALCULATIONS
The rules on heat loss and carbon emissions for extensions and conversions are complex. There are usually several ways of approaching building regulations for CO2 emissions. These are some of the issues which affect compliance with regulations:
- Usage - domestic or non-domestic
- Exact previous use of the building
- Whether there is a Change of Use, or a Material Alteration, or a Change of Energy Status
- Size of the extension
- Fabric standards
- Glazed area
- Limiting U-values
- Area weighted U-values
- The whole building CO2 emissions
- Extent of upgrades of the whole building
- Retained and /or renovated thermal elements, services and fittings
- Consequential improvement
- Historic buildings
- Type of extension, Conservatories
When I receive your drawings I will first study them to assess which approach would be most likely to achieve your objectives and advise you by email of this and of any recommendation for prior agreement or discussion with Building Control. I will also advise my fee and possible programme for carrying out the calculations. For this I need to make an initial charge, which will be deducted from the fee for the compliance calculations if you proceed.
I provide an all-in-one professional advisory service and assessment process on Building Regulations L compliance for all types of building project, including SAP (Standard Assessment Procedure), SBEM (Simplified Building Energy Model), DER (Dwelling Emission Rate), TER (Target Emission Rate), and EPC (Energy Performance Certificate) when required by Building Regulations.
Please post paper prints of the architectural drawings to my address below. If you have window dimensions on a drawing or schedule please include them. I calculate U-values for you and advise on the construction, air permeability (if relevant) and services that will achieve compliance.
The drawings should include elevations, plans, main sections, north point, outline specification for heating ventilation and air conditioning systems and for domestic hot water, and for lighting if available. I will contact you if I need any more information.
When I receive your confirmation that you wish to proceed::
I will email you to confirm the programmed date on which I will do the work. You will need to confirm the date, then arrange that I receive a cheque by the date of the work. If the job is urgent I may be able to fit you in sooner than I first indicate - please ask.
When I am doing the calculations:
· I will discuss with you any amendment to the design necessary to meet regulations. Usually I will telephone you for this.
I will send the completed report and calculations to you by email as a pdf file. You can email the file direct to building control.
I provide a fast, efficient, professional, personal service, with telephone support, for the majority of non-domestic buildings and for all types and numbers of dwellings. Please phone for current lead time. I can usually accomodate urgent work.
I have provided this service since 1995; my clients are numerous architects, developers, builders, surveyors, building professionals and self-builders. I am often recommended by building control officers.
PLEASE POST PRINTS OF DRAWINGS to:
SJ Kinsella CEng MIEE FCIBSE, KCE, The Old Forge, Kingston Bridge, Clevedon, Somerset BS21 6TX
email sjkinsella!AT!iee.org ( this address is written in anti-spam format – replace !AT! with @ )
First phone me on 01934
838624 if you wish........
OUTLINE OF BUILDING REGULATIONS L 2006 for non-domestic
buildings and dwellings - SEE
BELOW
Last Updated on 2/12/07
By Stephen Kinsella
Below...................
Notes on Building Regulations Part L and SBEM
Building Regulations 2006 L2 for non-domestic buildings
Building Regulations 2006 L1 for Dwellings
Building Regulations - Part L1A L1B and L2A L2B (approved document L) Conservation of fuel and power in England and Wales took effect on 6 April 2006
OUTLINE OF 2006 PART L2, for NON-DOMESTIC BUILDINGS
L2A NEW BUILDINGS
For new buildings calculations are required using BRE's SBEM program, or an approved equivalent. SBEM calculates all the L2 requirements for new buildings except for solar gain under Clause 64. I provide SBEM calculations and include further calculations for solar gain, to CIBSE publication TM37 as approved in Part L2 . I provide the stipulated Compliance Checklist.
L2A permits re-submission of calculations 'as built' on completion, showing that the building still complies, if air permeability is poorer than designed.
PART L2B EXISTING BUILDINGS
1) MATERIAL CHANGE OF USE
For a change of use, the approved document allows a means of compliance under L2b Clause 36. This sets standards for U-values of thermal elements and for heating, hot water , and lighting services.
If it is not possible to achieve compliance under Clause 36, greater flexibilty is allowed under Clause 37. For this calculations have to show that the CO2 emissions are no greater than if Clause 36 had been followed. This requires two sets of SBEM calculations, one as proposed and the other notional to Clause 36.
2) MATERIAL ALTERATION
For alterations, the approved document allows compliance under L2b Clause 39. This sets standards for U-values of altered thermal elements and for altered heating, hot water , and lighting services.
An SBEM calculation is not required. In difficult cases it is possible to provide an economic feasibility assessment to support a proposal.
3) EXTENSIONS
In accordance with L2b clause 25, for an extension of over 100m2 and more than 25% of floor area of the existing building an L2a calculation should be provided. Additionally, if the existing building has more than 1000m2 of floor area, consequential improvement in the existing building is necessary per Section 1 of L2b.
My calculations will include 1) SBEM output and 2) calculations for solar gain to TM37, required under L2a Clause 64, plus the Compliance Checklist
OUTLINE OF 2006 REGULATIONS for DWELLINGS
A. New dwellings (approved document L1A)
These are the main ways in which compliance is calculated:
1. Calculate the TER (Target CO2 Emissions Rate) for the dwelling, by substituting in the designed dwelling standard U-values (Table 2 on page 19 of the Approved Document) , glazed area, air infiltration, heating and fuel , and apply an improvement factor (currently 20%)
2. Calculate the DER (Dwelling CO2 Emissions Rate) with the parameters as required by the actual design, subject to some limiting conditions.
If the DER is better, i.e less than, the TER, the dwelling complies with this part of Part L.
3. Calculate the SAP rating.
4. Check internal and external lighting meets requirements.
5. Calculate summer condition to demonstrate that there is no tendency to high summer temperatures.
The assessment should be made for the design and again for the completed building.
B. Work in existing buildings (approved document L1B)
1. EXTENSIONS TO DWELLINGS:
a) Approach 1 - very simple
If the openings in the extension are less than 25% of floor area of the extension, ensure than U-values in extension meet standard values (Table 4 on page 22).
b) Approach 2 - quite flexible
Show that the average U-value of the extension is better than the extension would be with standard U-values and openings area.
c) Approach 3 - most flexible
Show that the CO2 emissions from the whole extended dwelling are no more than they would be for the dwelling with a notional extension built to standard U-values and openings. (Any improvement in the main dwelling cannot be included in this calculation, but is dealt with separately as below).
2. MATERIAL CHANGE OF USE:
If a dwelling is made in an existing building:
a) Simple method
New and replacement elements must meet thermal standards (Table 4 on page 22).
Retained elements must be upgraded if they are outside U-value threshold values (Table 5 on page 23).
b) More flexible method
Show that the total CO2 emissions are no worse than if the rule above had been followed. This allows for renewable energy sources, etc, to offset U-values.
3. MATERIAL ALTERATIONS:
When a dwelling is altered:
a) Show that retained and new thermal elements meet U-value criteria of Table 4 on page 22.
b) Ensure that retained thermal elements are upgraded if outside threshold limits of Table 5 on page 23, if economically feasible.
NOTES:
1. U-Value criteria:
The regulations look separately at:
a) Individual parts of the roof, walls and floors (i.e roof type 1,2 etc)where these differ in U-value.
b)The area-weighted average U-value of the whole roof, wall and floor.
There are different limits for each type and for the average.
2. Air infiltration:
For existing buildings a method of compliance is for work to be to Robust Details.
For dwellings in new buildings:
Either show by testing that air infiltration is less than 10 m3/hm2 at 50Pa
Or show by testing it is no worse than the infiltration used in the compliant DER calculation
Or (if no more than 2 dwellings of the type on a site) use a design value of 15 m3/hm2 in the DER. Compared with figure of 10 m3/hm2 this will necessitate improvements elsewhere to compensate.