What is Passivhaus?
Passive House, PassivHaus………..what is this that everyone is talking about? I've heard you can't open the windows; it is only for lentil eating sandal wearing vegans. Sounds expensive. Too many acronyms, MVHR, U-values, kWh, TFAs…..what does it all mean?
Put simply, the Passive House standard is a voluntary building standard, developed to assist in the design and building of super insulated low energy buildings with high levels of air quality, thermal comfort and low running costs.
Passive House buildings are characterised by the following features;
High thermal performance floors, walls, windows, doors and roofs. Insulation levels are typically 2-3 times the insulation required of a building to UK standards.
Windows are high performance triple glazed thermally efficient systems to reduce heat loss and promote solar gain.
The building fabric is enclosed in an airtight layer, reducing draughts. Air changes cannot exceed 0.6 air changes per hour. This compares to 7 air changes in a standard UK new build dwelling.
All rooms inside the thermal airtight envelope are ventilated by a mechanical ventilation system with heat recovery. This highly efficient system provides conditioned air to the rooms of the building, whilst recovering and reusing heat generated. Supply air is filtered to provide high quality air with low Volatile Organic Compound levels to the rooms within the building.
The Primary Energy demand of the building for heating, ventilation, hot water and appliances is limited to 120kWh/m2a.
Buildings that are specific to their location, engaging positively with their immediate site context to minimise their environmental impact.
But what does this all mean? Essentially you will have a building that;
Has a high level of thermal comfort throughout the year. Warm, snug rooms without any draughts or cold spots in winter, and cooler rooms in summer.
Lower energy bills and protection from fuel price rises.
An average UK Home's Primary Energy demand is around 300kWh/m2a. At 68m2 (average UK house size), that's in excess of 20,000kWh of energy each year. The equivalent Passive House would use 8,160 kWh, around 40% of the energy, saving upwards of 60% on energy bills annually.
Cleaner, healthier air quality inside. Less allergies, better sleep, improving health and well being and concentration.
Low maintenance costs. Less technology to go wrong, so there are fewer heating emergencies and expensive repairs. No high explosive devices such as a gas boiler in your home!
Peace and quiet when the windows are shut.
More wall space, as you don’t need any radiators – giving you more choice of where to place pictures, pianos or sofas.
Far superior build quality compared to standard building techniques.
A home that is unique, enhanced and engaging with its immediate surroundings.
Why choose a Passive House?
If you want to protect yourself from fuel price rises. Extremely low running costs.
If you value thermal comfort and a clean, healthy internal environment in your home.
To ensure that you are investing in a well built home.
To minimise your impact upon the environment and climate change.
If you value living in a home that is dynamically engaged with its immediate environment
The Passive House standard is simply a set of measurable outcomes targeted to deliver a well designed environmentally friendly home for you and your family. The buildings need not be complex and do not rely on fancy, expensive bolt on technologies to achieve their outstanding performance. Rather, they are well thought through, simple, well built buildings that engage in a positive manner with the environment to produce a low energy, low cost, healthy home for you and your family.
As Certified Passive House Designers, Novo Design Studios is well placed to advise on successful Passive House Design. Alongside designing fully certified Passive Houses, we utilise the strategies and techniques in all of our house designs to achieve as high an environmental performance as the brief will allow, delivering well detailed, contemporary, healthy homes for our Clients. If you would like to discuss how you could implement some of the ideas outlined in this article, get in contact with us and we would be glad to help.
Sources
Average UK Home 67.8m2 - LABC Warranty/ Which April 2018.
OfGem TCDVs (Typical Domestic Consumption Value) for 2017;
Gas 12000 KWh
Electricity 4200 KWh
Total Energy demand - 16200 kWh or 239kWh/m2a