sustainability advice

Thermal Imaging Service - click here for more details

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Our sustainability services cover:

 

Airtightness testing

Airtightness testing of new dwellings is now mandatory for developments of over two units in England and Wales. A sample of each type of dwelling must be tested and be within the air leakage rate stated in the dwelling's SAP calculations.

 

For one or two units, airtightness testing is not mandatory, but an 'assumed' air leakage rate above the industry norm must be made. Often, it is simpler and more cost-effective for builders to test to prove a lower air leakage rate than to find more complex ways to demonstrate energy saving.

 

The Approved Document Part L1A for work in new dwellings will require, with few exceptions, type-testing of all new dwellings to an airtightness standard of no greater than 10 m3/(h.m2) at 50 Pa. For some dwellings where the carbon emission rate is difficult to meet for architectural reasons, then the airtightness target under the SAP calculations may need to be reduced to 7, 5 or even 3 m3/(h.m2) at 50 Pa to meet the overall carbon emission rate required by the
Regulations.


Uncontrolled ventilation in dwellings through leakage paths around doors and window frames accounts for a significant proportion of heat loss, particularly as the insulation values of walls and glazing has improved. In order to control this energy loss, the Building Regulations will regulate the overall leakage of the building structure by testing, using a pressurising/depressurising fan method. This document specifically covers the methods used to comply with the airtightness component of the Regulations.

 

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Air permeability

 This is the same standard of airtightness as introduced in Part L2 of the 2002 Building Regulations for buildings with a gross floor area exceeding 1000 m2.  Essentially, it is the amount of air required to pressurise and/or depressurise a building to 50 Pascals (Pa), normalised with respect to the building's envelope area.

 

Envelope area is defined as the internal surface area of the external walls, roof and footprint of a building. A building's footprint is usually defined by the area of the ground floor slab, except where the building has a basement. The roof area is normally defined as the area below the loft, where the loft is not an accommodation area (in other words not conditioned). The area of external walls is only true for detached properties. Semi-detached and terraced properties will have party-wall elements.

 

Quality of construction

 

While the maximum allowable building air leakage rate is 10 m3/(h.m2) at 50 Pa, designers may choose to create an even more airtight construction (7, 5 or even 3 m3/(h.m2) at 50 Pa) and to use the calculated energy saving to trade off against other building details. It is likely that terraced houses will have the greatest difficulty in meeting the Dwelling carbon dioxide Emission Rate (DER), and will require a tighter air permeability specification. The DER should be less than the Target carbon dioxide Emission Rate (TER).

 

Where U-values for elemental type, allowable areas of windows or doors, and quoted efficiency of heating appliances do not (in total) enable the dwelling to meet the required TER, then the target air permeability may need to be lower than 10 m3/(h.m2) at 50 Pa.

 

This is the same standard of airtightness as introduced in Part L2 of the 2002 Building Regulations for buildings with a gross floor area exceeding 1000 m2. Essentially, it is the amount of air required to pressurise and/or depressurise a building to 50 Pascals (Pa), normalised with respect to the building's envelope area.

 

Envelope area is defined as the internal surface area of the external walls, roof and footprint of a building. A building's footprint is usually defined by the area of the ground floor slab, except where the building has a basement. The roof area is normally defined as the area below the loft, where the loft is not an accommodation area (in other words not conditioned). The area of external walls is only true for detached properties. Semi-detached and terraced properties will have party-wall elements.

 

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Acoustic testing
calfordseaden offers UKAS accredited acoustic testing for Part E of the Building Regulations on all types of buildings, based on BS2750 Part 4 and Part 7. We supply detailed reports of the whole survey, stating the level of acoustic separation and include details of problem areas.

 

We conduct airborne and tapping sound tests across rooms sharing a wall and sharing a floor. BSRIA:

 

  • provides detailed reports of acoustic performance and make practical recommendations for improvements if necessary
  • conducts tests outside normal working hours to minimise site disruption and avoid construction site noise
  • offers a "one-stop-shop" compliance solution alongside airtightness and thermographic testing.

 

Under Part E of the Building Regulations, a sample of units in new dwelling developments and refurbishments may have to be tested to demonstrate levels of sound insulation. This has now been extended to new schools and is also regularly specified by clients of buildings where sound can be an issue, such as hotels and nightclubs.

 

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Air conditioning inspections

Many private and public sector buildings and an increasing number of homes have air conditioning systems. These systems must be carefully sustained and managed so that they do not consume too much energy. Measures have therefore been introduced by the Communities in Local Government (CLG) to ensure that the larger air conditioning systems are regularly inspected in all properties. AC Systems installed after 1st January 2008 must be inspected within 5 years of installation. Existing AC systems over 250kW must be inspected by 4th January 2009. Existing AC systems over 12kW by 4th January 2011.

 

The inspection report must include an assessment of the air conditioning efficiency and the sizing of the system compared to the cooling requirements of the building, and contain appropriate advice on possible improvements to the system, replacement of the system and alternative solutions. Our Energy Assessors are accredited to inspect AC systems and typical their inspection would include:

 

  • Documentation review.
  • Comparison of maintenance with industry good practice.
  • Inspection of system components.
  • Assessment of controls and settings.
  • Estimation of cooling load.
  • Review potential for improvement or alternatives.
  • Report on the findings and advice.

 

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Thermal Imaging - How do your buildings perform?

Through the use of thermal imaging, calfordseaden are able to analyse and review the thermal energy performance of buildings whilst in operation and target where improvements to these buildings should be made.

 

calfordseaden are using this technology to review building performance as part of our condition and energy surveys. We are able to easily demonstrate to our clients the performance of their new and existing stock, including buildings within the residential, commercial, health and education sectors.

 

Discover more about calfordseaden's thermal imaging service.

 

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