Coat House – the low-energy house of the future

Coat House – the low-energy house of the future

Situated on a hill in the Danish town of Kolding, overlooking the lake and historic castle, is a vision of the future. A house dating from 1949 has been externally insulated, and thereby transformed from a draughty and expensive-to-heat dwelling to a modern and contemporary residence with an 85% lower heating bill.

Christened 'Coat House', the facelift is a development and demo project carried out under the 'Green Business Growth' initiative. The purpose of the project is to inspire architects, tradesmen and citizens to adopt new methods of energy renovation.

Coat House Fiberline Composites

Final calculations now show that 'Coat House' not only meets but also beats initial expectations! 

Coat House has since 2009 undergone an energy renovation which is quit unprecedented. The building was originally constructed of aerated concrete and equipped with a slate roof. The external walls and attic space were badly insulated and the windows were made of wood fitted with elderly double glazing.

The energy renovation consisted of externally wrapping the building in 'overcoat' consisting of insulation and a fibre shell. This overcoat was constructed of three layers: 'sweater', 'fleece' and 'raincoat'.

Coat House Fiberline Composites Coat House Fiberline Composites

The existing outer wall was clad with a 300 mm layer of insulation followed by Eternit sheets surfaced with Fiberline facade planking. Existing window and door frames were replaced and triple glazing was fitted. The new window and door profiles consist of thermal-insulating composite.

The house is equipped with a heat recovery system which heats the air taken into the building with the air taken out. The recovery efficiency is around 90%.

Ventilated facade
Coat House is equipped with a 'ventilated facade', which offers a number of benefits:

  • Reduced condensation due to continuous effective ventilation
  • Reduced noise from outside
  • Increased energy efficiency both summer and winter
  • In winter the ventilation dries the construction, therebv increasing the degree of insulation
  • In summer the warm air in the cavity rises and is replaced by cooler air. This helps maintain a pleasant and comfortable indoor climate.

Coat House Fiberline Composites

Energy renovation has tremendous potential
With modern and relatively simple technology that is quick and easy to fit this method of insulation can be used to give elderly, worn-out buildings a fresh, new look while at the same time reducing energy consumption. In the case of Coat House by more than 85%.

With this project it is the intention of Fiberline and Saint-Gobain Isover to show building tradesmen and home owners how to modernize a building's appearance and at the same time provide effective insulation. The result is a future-proof building which also satisfies new carbon standards.

If Denmark is to meet its international obligations to reduce carbon emissions and achieve its goal of becoming independent of fossil fuels, energy renovation is an area which offers tremendous potential. No less than 40% of Denmark's total carbon emission is produced by buildings, and flats and houses built between 1930 and 1975 have the highest emissions. According to the Danish Building Research Institute, Denmark can save around 830 million litres of oil a year, or 32% of total consumption, by means of further insulation and by replacing windows. Despite this huge potential, energy renovation is given low priority in Danish domestic modernization projects.

Coat House Fiberline Composites

Expectations surpassed
Fiberline was expecting the annual energy consumption for Coat House to be reduced from 240 kWh/m2 prior to the energy renovation to 33 kWh/m2 afterwards, a saving of more than 85%. This reduction would already qualify Coat House as a low-energy class dwelling in accordance with the year-2015 target stated in the Danish Building Regulations (BR10).

In March 2011, new calculations showed that Coat House had not only met but outperformed these expectations.

To meet the year 2015 target, the annual energy requirement of Coat House must not exceed 32.9 kWh/m2. The final calculations show that the total annual energy requirement will not exceed 32.6 kWh/m2, which is therefore within the stated limt limit (see Factbox).

What's more, Coat House can potentially reduce its annual energy requirement still further, by 5-6 kWh/m2 as it is equipped with pipes for geothermal heating. However, the contribution from such pipes is not included in the calculations according to BR10.

Create your own Coat House

  • It is a good idea to start by contacting an architect to help design the solution
  • You may need to contact the following for further information:
  • Saint-Gobain Isover (insulation system)
  • Nilan (heat recovery system)
  • Pro Tec (low-energy glazing)
  • Fiberline Composites (facade planks) 

Coat House Fiberline Composites

Collaboration partners

Coat House is not only an example of successful energy renovation, but very much also an example of successful collaboration. Several parties were involved in the project, each with their separate competencies:

  • Fiberline Composites and Saint-Gobain Isover jointly developed the insulation system
  • Fiberline Composites supplied the facade cladding
  • Middelfart and Kolding local authorities supported the project as part of the 'Green Business Growth' initiative
  • Architect Sofie Thorning designed the modernization and new facades
  • Tegnestuen Mejeriet headed project planning and supervision
  • Pro Tec supplied the new window system which includes Fiberline's window profiles
  • Nilan supplied the ventilation system

Coat House Fiberline Composites Green Business Growth 

Facts about the Danish Building Regulations (BR10)

BR10 specifies that dwellings in Low Energy Class 2015 must use 43% less energy than buildings built according to standard requirements and must not need the supply of more energy for heating, ventilation, cooling and hot water than is determined by the following equation:

30 + (1000/A) = kWh/m2 per year  (A is the heated floor area)

Coat House has a floor area of 345 m2

According to the equation, the energy ceiling for for Coat House is 32.9 kWh/m2