Case Study:
Achieving Part L compliance with natural gas

A gas boiler and solar photovoltaic solution, one of many ways of complying with Part L using natural gas.

Commitment to continuous improvement

Frisby Homes have been at the forefront of quality house building in Waterford for over 35 years. Fox Wood is Frisby's latest project in Waterford, combining the very latest Building Standards with quality construction. 

By investing in highly efficient gas boilers complete with renewable technologies and very high standards of building fabric, Frisby Homes have constructed sustainable, comfortable and energy efficient new homes using natural gas and photovoltaic (PV) panels.

System Features

92% Efficient Gas Boiler

5 Solar PV Panels

95 litre Stainless Steel Water Cylinder

Weather Compensater

The following input values are used in this example

Building Fabric:

Compliant with U-Value Requirements

Floor: 125mm of PIR insulation   

U-Value of  0.138 W/m2. K

Walls: 360mm Cavity 100mm XT/CWP    

U-Value of  0.17 W/m2. K

Roof: 400mm of Rock Wool

U-Value of  0.11 W/m2. K

Windows: Double-glazed windows  

U-Value of 1.4 W/m2. K

Heating System:

≥ 90% Efficient Boiler

Main Heating System
92% efficient gas fired condensing boiler with standard size radiators. This means the heating system is inslalled using traditional elements, so there is no need for the use of expensive aluminium radiators.

Heating Controls and Water Storage
Time and temperature zone controls are achieved by a simple time-clock and thermostats within the system. This in conjunction with a 95 litre stainless steel water cylinder including insulation of 30mm thickness, makes this one of the most economical solutions on the market.

Secondary Space Heating
The 6kW fuel burning stove is a great focal point in the living room.


Natural Ventilation throughout the house

THe double glazed,argon filled, passive house stnadard windows further reduce heat loss and all wet rooms include a simple extract fan. Current air tightness testing method determined air filtration to be just over 0.19 air changes per hour of floor area. This is accomplished using 'A' rated tapes and sealants, elimanating draughts and reducing heat loss.

Renewable Energy Contribution:

10 kWh Thermal Renewable Energy per metre squared per year

The houses on this development require 5 solar PV 280W panels. Fox Wood easily complies with the thermal renewable energy contribution requirement of 10kWh per metre squared per year with a thermal equivalent of 28.54 kWh per metre squared per year.

Performance Coefficients:

Carbon Performance Coefficient (CPC) <0.46 & Energy Performance Coefficient (EPC) <0.4

Natural gas as the primary heating system combined with other renewable technologies comfortably meets Part L Building requirements for EPC <0.4 and CPC <0.46. In this development values of 0.282 for CPC and 0.315 for EPC were achieved.

What is Photovoltaic Technology?

Photovoltaic Technology

Photovoltaic (PV) panels generate electrical power by converting solar radiation into free electricity. The photovoltaic system provoided by Construction PV consists of solar panels collecting light energy from the sun that is then converted to supply electricity to the home. The solar panels are modular in their approach and can be either integrated into or mounted on the roof.

Free energy

The solar energy provided by PV panels is free energy. THis free energy contributes to the running of electrical appliances in the house and therefore reduces the homeowner's electricity bill. Excess PV energy can also be diverted to the hot water tank therefore reducing overall running cost.

Meets Par L compliance easily

The combination of natural gas, renewable technology and high standards of insulation means this development surpasses all of the Part L Building Regulation requirements iin using a cost effective approach. With natural gas, homeowners are guaranteed a fully 'A; rated solution.

Natural gas - A unique selling point:

For the homeowner

Owners of these homes will be able to come in, switch the heating on and enjoy instant and controllable space heating and hot water. This energy solution is cost effective, clean, efficient and user-friendly ehich is exactly what homeowners want.


For the builder 

A house with natural gas is a home. It is instantaneous, easy to control and versatile. When the levels of insulation used are combind with natural gas and PV panels, the Fox Wood hoemowner has a complete system that is on par with the most economical solutions available.

Fox Wood Case Study PDF

Why choose natural gas

The most reliable energy solution

Enjoy a constant and uninterrupted supply with no need to order or schedule deliveries. Piped straight to your house or premises, say goodbye to bulky fuel tanks and storage areas.

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