Summary of Designers and Builders requirements

Reference should be made to the complete guide – Series 24 Guide 4 - L1A Conservation of Fuel and Power 2006 - New Dwellings.

Design Stage

1. SAP or SBEM calculations to be submitted showing the TER and DER compliance.
2. Designs and plans must reflect the design solutions chosen in the above calculations – ensure you make the builders aware of the key elements of the thermal design necessary to achieve maximum CO² emissions to avoid issues developing in the construction stages.
3. The building envelopes elements must not have 'U' values greater than the 'Limiting U-value Standards'. You must provide evidence of their performance e.g. 'U' value calculations. Be careful using only the minimum standards will lead to a likely fail in the DER.

   Certain assumptions will be made around the dwelling’s primary heating systems, secondary heating systems, mechanical cooling and ventilation systems, insulation of pipes, ducts and vessels e.g. compliance with the ‘Domestic Heating Compliance Guide’ etc; and that 30% of the lighting systems will be low energy; and that appropriate passive control measures to limit effect of solar gains on indoor temperatures are achieved.

   You must ensure that the builder does not lose sight of these and that due regard is given to them at the construction stage if the building DER is to comply. Changes or additions to these areas of construction can have significant effects on the dwelling’s CO² emissions.

4. The DER calculations will also assume that the dwelling(s) will be constructed with a maximum design air permeability of 10m3/(h.m2) at 50PA. As a designer you must ensure you follow robust detailing to limit cold bridges and air leakage, if this is actually to be achieved during the construction stage. Remember an air test is to be undertaken on completion and a test failure would have serious implications on having to carryout remedial works to completed dwellings.

5. In order to pull all the above issues into some order, you will be required to provide a completed L1A checklist for each dwelling on application submission (available at the rear of the Approved Document or Tameside Building Control Web page). Ensure a copy is also provider to the builder, so that he is made aware of the ‘Builder’s Submissions’ requirements on completion.

Construction stage

1. You must not make changes to the designs and construction specifications without checking on the implications to the buildings DER.
2. Air permability – you must ensure that a robust regime of air leakage sealing and that all cold bridges are eliminated in the construction.
   
   A ‘suitably qualified person’ i.e. project manager or site agent, will be required to complete for each plot a ‘Declaration of Continuity of Insulation’ and this must be provided to Building Control on the plots completion.
3. Which plots are to be pressure-tested are to be agreed with Building Control – then on arrange for pressure testing in accordance with Measuring Air Permeability of Building Envelopes – ATTMA 2006 to be carried out by an approved testing body or person.
   
   Copies of the Pressure Air Test must be provided to Building Control, not later than 7 days after the final test is carried out.
4. Provide a completed the L1A checklist for each dwelling plot – with sufficient information to show that the ‘Builder’s Submissions’ requirements comply with the relevant requirements.
5. Provide a copy of the fixed building services notice, confirming that commissioning has been carried out in accordance with an approved procedure set out in the ‘Domestic Heating Compliance Guide’ by a suitability qualified person. This must be provided not more than 30 days after the works completion.
   
   Copy also to be provided to the new building owner
6. Provide the owner sufficient information about the building, the fixed building services and their maintenance requirements to allow the energy saving provisions to be maintained e.g. provide simple set of operating and maintenance instructions relevant to the particular systems installed in a durable format.
   
   Instructions must show:

   1. How to adjust timers/temperature control settings and:

   2. What routine maintenance is required to maintain operating efficiency throughout the system’s service life

7. Provide a final ‘As Built’ ‘DER’ CO² Emission Rate Calculation and Certificate for each dwelling - reflecting any adjustment in performance between design and construction and to demonstrate that the building as constructed meets the TER.
   
   This must be prepared by a suitably qualified person and provided to Building Control NMT 7 days after the final Air Test was carried out or where no air testing is required 7 days before the final completion inspection is carried out.
8. Finally ensure that a copy of this the energy rating calculation and certificate is fixed in a conspicuous place in the dwelling at least 5 days before occupation.