April 6th 2006 so the introduction of new Building Regulations relating to Ventilation, Conservation of fuel and power, and Electrical Safety.

To assist you in understanding the new regulations we have provided information relating to the changes including a summary of Approved Document L1B

The document available for download is a "paper" presented to the West Yorkshire Building Control Group. It outlines why the regulations have changed and what the objectives of the changes are. The document outlines the basic content of the regulations relating to Part F - Ventilation,  Part L - Conservation of fuel and power and Part P - Electrical safety.

The new Approved Documents are available from the ODPM web site  

Approved Document L1B - Conservation of fuel and power in existing dwellings  

The content of the new Approved Documents is complex. This web page is intended as an introductory summary with minimum technical detail and should not be relied upon as a substitute for the full L1B Approved Document.

This web page contains tables detailing the maximum U values that are permitted for certain roofs, wall and other parts of dwellings that are being altered or extended.

Introduction

Approved Document L1B provides guidance on what, in ordinary circumstances, will meet the requirements of the regulations when carrying out work on existing dwellings.

For the first time, in certain circumstances, there is a requirement to upgrade the existing buildings thermal performance (consequential improvements). As usual there are also slightly less onerous requirements for historic buildings, provided the Authorities conservation architect is in full support of the reasons for relaxing the requirement.

Extension

U-values for new pitched roofs with insulation between rafters or at ceiling level are unaltered but all others are reduced. The new maximum U-values are:

Areas of windows, roof windows and doors should not be greater than 25% of floor area of the extension plus area of the extension plus area of any windows or doors no longer exist or no longer exposed as a result of extension works.

The new Approved Document also provides optional approaches to allow more design flexibility concerning U-values or, alternatively, SAP 2005 can be used.

Change of Use

The new Approved Document provides more detailed guidance than was previously available concerning buildings or parts of buildings being converted to dwellings:

New thermal elements (walls, floors and roofs) are to have U-values at least that as given above.

Where more than 25% of the surface area of an element is being renovated, the whole of the element will need to be upgraded to achieve the following U-values.

Where existing thermal elements are to be retained, and are below a specified 'threshold U-value', they will need to be upgraded to achieve the following U-values.

For thermal elements being retained or renovated, guidance is provided to cover circumstances where improvement may not be technically or functionally feasible, or would not achieve a simple payback within 15 years.

SAP 2005 can also be used as an alternative approach.

Controlled Services or Fittings

In an extension, windows, roof lights, roof windows, and doors with more than 50% of the internal surface area is glazed, need to meet the prescribed U-values. Less onerous U-values apply when replacing fittings in the existing dwelling.

The Approved Document requires that new heating or hot water systems should have efficiency not less than that recommended for its type in the Domestic Heating Compliance Guide (not yet published).

The document includes provisions for replacement heating or hot water systems and the Domestic Heating Compliance Guide details requirements for controls and standards for the insulation of pipes and ducts.

Guidance is also given where mechanical ventilation or mechanical cooling is to be provided.

The minimum requirement for fixed internal lighting is the greater of, one energy efficient light fitting per 25 square metres of dwelling floor area (in areas affected by the works) and one per four fixed light fittings.

Copies of the formal documents are available on the ODPM web site.

Construction that meets the new regulations 

With regards to Conservation of fuel and power the range of building products available which when included as part of the building construction will meet the new standards is extensive, therefore to help you achieve compliance with the regulations we have put together a table of insulating products which are used on a regular basis throughout Leeds and West Yorkshire. (See pdf file)

Note
The products specified are only a selection and we must stress that we do not endorse any manufacturer whose products are listed, others are available that are suitable and will also achieve compliance with the regulations.

To assist further links to several web sites are provide. These will provide additional information not just on insulating products but also on the subject of Energy Conservation and how to reduce your annual fuel bills.

Web site disclaimer
Any links contained in any part of our pages to these or other Web sites are provided solely to help you browse this topic. We do not endorse any of the products or manufacturers. There is no control by us over the content in these sites. If you decide to use them, you do so entirely at your own risk and we cannot be held responsible for any material which may appear on them, or loss resulting from their use.