Air Tightness & Insulation

Energy efficient house – saves money

How to heat & conserve energy falls under a number of headings.

  • How to heat a dwelling – oil, gas, geo-thermal & wood pellet.
  • Lighting energy within the dwelling – LED lighting and PV panels.
  • Water use in dwelling – heating of water, rain water harvesting.

How to heat and the use of energy are at the fore front of people’s minds. The most efficient way to heat their new home / new extension or to upgrade of an existing home . There are a lot of “buzz” words being bounced around in today’s media & marketing ploys. Such as BER certs, geothermal – air to water unit or ground source or bore hole, air permeability in a building, solar tubes or flat plate.

We as a construction firm have a keen interest in this area. We keep up to date with the latest in heating & energy requirements as part L of the Building regulations & best practice in the different energy heating.

Having a proven track record in airtightness to buildings, insulation methods, heat recovery units & the various heating pack for houses i.e. solar, oil/gas, geothermal. We have experience with all of these areas. We have & can give the benefit of our experience to any of our new or existing clients.


An integral part of a building, we have an electrical contractor who has worked with us on various projects over the last 10 years. Our contractor can advised at drawing stage of a lighting layout such as mood lighting, different levels of light e.g. reading level, low level lights, dimmers in various rooms, security lights to external , intercom, surround sound for TV or iPods’ throughout the house. Lighting and socket layouts to rooms and kitchen.

BER certificates

A BER is an indication of the energy performance of a new or existing home. It covers energy use for space heating, water heating, ventilation & lighting. The BER is calculated on the basis of a standard occupancy. A BER rating goes from A1 most efficient to E least efficient. There are sub divisions to the ratings A, B, C i.e. A1, A2, A3 etc. So the BER cert for your home depends on how efficient you house performs in a DEAP calculation.

We have an independent BER accessor in our team of professionals that can advise and perform the BER certificates.

Air tightness

Air tightness or air leakage is a big part of the energy conservation of a building. Why would you allow cold air to leak in to your house or allow warm air to escape through the envelope of the building e.g. air gaps around windows, doors, floors, light fittings.

Siga are world leaders in air tightness to buildings. We are Siga approved installers of airtight membranes and tapes. We have being on courses up skilling in this area. We have achieved an airtighness test level of 1.19 ac/h to a block built house. Giving a result of 1.60 m3 h m2. And having worked on a timber frame house achieving 0.6095 in an air tightness test. The current building regulations (Technical Guidance Documents part L) have a maximum upper limit of 5 m3 h m2 .

Best practice in domestic dwellings calls for an ac/h rate of not more than:

  1. 3.0 ac/h – natural ventilation ( wall vents)
  2. 1.5 ac/h – with mechanical ventilation ( HRU)
  3. 0.6 ac/h – passive house standard


There is a number of types of wall insulation on the market and different types of methods in the uses of insulation such as traditional cavity insulation, cavity insulation with a thermal board on the inside leaf, single panel timber frame filled with cellulose, or timber frame and a block external outer skin. Cavity wall filled with insulation. U valves of 0.15w/m2 can be achieved to external walls or lower if required. Also equally low levels to of .013 to attic and floors at affordable prices. We have being involved with all of these types of construction and can provide our opinions on each if requested.

Heat recovery units

Heating recovery units (HRU) become efficient when an air tightness of less than 1.5 ac/h is achieved. We have used these units on a number of projects. A fully insulated duct passing through attic space is required to stop condensation building up in the ductwork exhaling warm moist air out of the building. If condensation is allowed to build up in the ductwork this can lead to mould growth in ducts.

Heat pack

A heat pack is describe as a unit that heats a building, such as – oil/ gas condensing boiler, solid fuel, wood pellet & geothermal – ground source, air to water, bore hole, solar panels. Having experience with all of the heat packs we can advise if required.

The most efficient way to heat a house is to keep the heat pack off for as long as possible. And to do this is by proper insulation & air tightness. If a house is not losing heat the heating pack takes a shorter time to heat the building and thus saving you money in return.