The objective is to help provide a blue-print for greening period properties. There are thousands of beautiful period properties in the UK that are becoming a financial burden through energy costs and yet their integrity must be preserved. If these buildings are not preserved encompassing low energy design they will increasingly become financially unsustainable. Simple energy saving measures applied in modern homes do not necessarily apply to period properties as they may be aesthetically unsympathetic or damage the sensitive fabric of the building. Making a period property efficient is much more challenging and information on best-practice is harder to come by.
Current energy costs for the house are in excess of £12k per year. Within 10 years this is likely to double; making the home economically non-viable.
The primary objective is to provide a route map of how to sympathetically 'green' this period home and make it financially and environmentally sustainable. Without investment now continually rising energy costs will simply render this house economically non-viable, making it a liability rather than an asset.
Using an unrealistic retro-fit methodology with exotic materials would also render the project non-viable from an economic perspective. We will therefore try to use a combination of traditional craftsmanship and mainstream mass-produced building products to help make the project economically viable.
By reducing energy consumption as much as possible the home will be cheaper to run and have a much smaller carbon-footprint.
We will reduce energy consumption whilst preserving the ancient fabric of the building and remaining mindful of the embedded CO2 in the materials employed in the project.
Principles of Design
1st: Save Energy
Our primary objective is to reduce the energy-load consisting of gas, electricity, wood; and to remove the need for heating oil completely.
In order to do this irrespective of the active technologies installed our first requirement is to save energy through the application of passive technologies. To do this we are planning to:
- dig out existing earth-floors and re-lay with solid insulation and a wet underfloor heating system
- remove the roof, replace rotten timbers and heavily insulate creating a warm-roof, then replace the roof covering with suitable pantiles
- internally insulate the external stone walls
- sympathetically replace or draft-proof existing doors and windows. In order to preserve some of the period sashes we will employ ultra-thin low-energy double glazed units.
2nd: Use Energy Wisely
We also plan to install a wide range of low-energy and energy management technologies.
These will include:
- Energy efficient lighting and appliances.
All lighting and other goods in the home will be as energy efficient as possible: eg. using LED lamps instead of compact fluorescent or filament lamps.
- Multiple zone thermostatically controlled heating.
By monitoring and carefully controlling the temperature of different areas heating energy will be saved and the home will be kept at a constant comfortable temperature. This will also be aided by the high thermal-mass of the internal walls.
- Mechanical ventilation and heat recovery (MVHR).
The principle of MVHR is to extract the warmed stale air form the home and pass it through a heat exchanger that warms the fresh air coming into the building. This technology is still rare in modern homes and is not usually employed in older buildings because of their poor draft integrity. It is therefore essential that all building works are mindful of air-tightness.
A well designed MVHR system will aid fresh air ventilation ensuring a healthy-house free from toxic chemicals but it will also help overcome any potential problems with damp caused by insulating and draft-proofing this older house.
- Smart-energy control systems
Designed to optimise energy from renewable energy when it is available. We will switch electrical loads on and off at times when we are getting generation from the solar PV array. By doing this we will not need to install a solar thermal system as we can heat the domestic hot water electrically.
- Rainwater harvesting
This will be used to reduce the home's demand for mains water. The large roof area is an asset for collecting a large volume of rainwater. The home will also be completely re-plumbed giving the opportunity to use the collected rainwater for flushing of the WCs and gardening etc.
3rd: Generate Energy Using Renewable Technologies
- Solar Photovoltaics (PV):
A 25 kWp array will be mounted on the ground at a distance (150m) from the house. This will ensure the system does not affect the delicate aesthetics of the house but it will also be an opportunity to install the PV array in the most efficient configuration possible (south facing, 30 degree elevation, zero shading). Across the year this will generate electricity to meet the home's annual demand. The solar PV array will also generate an income through the Feed In Tariff incentive scheme. This should be sufficient to not only cover all the electricity costs for the home but also generate a tax-free revenue stream for the next 20 years. This will help subsidise most other energy costs for the home.
A 40kW Biomass Boiler will replace the existing 50kW gas boiler. The benefit of employing the biomass boiler is that not only is the fuel locally sourced but it is a low carbon technology. This method of heating will also generate a profit/revenue stream thanks to the Renewable Heat Incentive (RHI) scheme.