WindowsThere are a number of opportunities for upgrading glazing during a refurbishment project. Consider:
- Triple glazing: This is still quite specialised so expect to pay a premium. Payback over double glazing can be achieved in a few years and on exposed northerly facing windows or in noisy urban locations, the improved comfort could make triple glazing a viable option.
- High performance glass:
A special 'low emissivity' coating reflects heat, keeping internal heat in and external heat out. The warmer internal pane improves comfort levels and reduces condensation. Solar control films offer a cheaper retrofit option but always seek specialist help prior to carrying out any work.
- External shading: Installing shades to the outside of a building can allow winter sun to enter a space (providing daylight and letting in more warmth) whilst reducing the impact of direct summer sun. Planting deciduous trees and shrubs can also be effective as foliage provides shading during summer, whilst bare branches let maximum heat and sunlight through in winter.
DoorsThe thermal performance of doors has improved over recent years. When purchasing new doors, it is important to consider their thermal, fire and security performance and access characteristics. Take care when sourcing products outside the UK as it can be difficult to check what standards these doors meet.
- Fit draught lobbies:
This is a cost-effective method of reducing heat lost from main entry doors. Ensure there is enough space between the two sets of doors to allow one set to fully close, prior to the other set opening.
- Consider options for vehicular access doors: These large openings in the walls of a building can result in high heat losses and would benefit from the installation of air-locks, PVC curtains, warm air curtains or high speed motorised doors with automatic opening and shutting controls.
WallsEnsure cavity walls are filled with insulation, unless the building already suffers from rain penetration. Insulation measures for solid walls are more expensive and disruptive so should be considered during major refurbishment projects.
- External insulation: Insulation board is applied to the external fabric of a building and protected by a specialist render. Note that the proposed new surface finish must be acceptable to the planning authority and should be applied in accordance with manufacturer’s recommendations.
- Internal wall insulation: This option is less expensive but more disruptive. Heavy items such as radiators will need to have supports. While any service penetration - e.g. for electric sockets and pipework - should be minimised to maintain the integrity of the insulation.
- Exposing the fabric: When exposed to internal air temperatures, heavyweight building fabric (like concrete) can act as a sponge, absorbing heat and allowing a building to heat up more slowly and hold its temperature for longer. This can reduce peaks and troughs in internal temperatures and prevent overheating during occupied periods.
Exposing the walls and ceilings in steel and glass buildings will not provide significant thermal 'buffering' benefits. This is because steel and glass do not absorb and retain heat as effectively.
RoofsEnsure accessible pitched roofs have adequate insulation installed. For flat roofs, insulation is generally only cost-effective during replacement or refurbishment.
- Flat roofs:
Make sure insulation is added whenever a flat roof is being replaced. Insulation can be applied internally, externally or above a suspended ceiling. Where insulation is already present, adding to it will generally save money in the longer term. However, the more insulation already installed, the longer the payback periods will be.
Ceilings and floorsConsider improving insulation between floors. This reduces overheating on the upper floors of a building, and prevents the lower floors from feeling too cold.
- Suspended timber floors:
Seal gaps in skirting and between floorboards of suspended timber floors to save 1% of total heating fuel costs.
- Concrete floors: Installing insulation to suspended ceilings may be more cost-effective than focussing on the floor. On ground floors, ensure insulation is installed whenever a new floor is to be laid.
- Insulate between ceiling spaces: This reduces underheating on lower floors and overheating on upper floors of a building. Take care to ensure any electrical cables sharing the same space have enough room to prevent them from overheating.
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