Passivhaus
The Passivhaus Institute's rigorous low energy building standards, Passivhaus & Enerphit, ensure the highest levels of comfort, efficiency and sustainability for your project. We use the latest energy modelling analysis, a deep understanding of building physics and high-quality robust materials to ensure your building benefits from significantly lower bills, exceptional indoor air quality and thermal comfort, while bringing our design flair to create joyful elegant spaces with abundant daylight and connection to their surroundings.
Our Approach
Part of the appeal of the Passivhaus design standard is its simple yet strict energy criteria, however we feel a good design is not just about energy efficiency! We always aim to specify natural materials and carefully consider the embodied carbon of the finished building and its construction method, whilst celebrating delight and finesse within the design. Balancing all of these design factors requires significant skill to achieve, but with our background in low energy and sustainable design we are up to the challenge. Our inhouse Passivhaus Certified Designer has also undertaken the Advanced Passivhaus Consultancy course.
Passivhaus standard | New Build
Enerphit standard | Retrofit (existing buildings)
|
Passivhaus Principles
The Passivhaus design process works with the local climate to optimise comfort in your building while minimising the need for active heating and cooling. Initially this involves analysing the most efficient form and layout to meet with your design requirements, while carefully considering the building fabric and site context to optimise solar gains.
A well insulated and airtight building significantly reduces unintended heat loss through the building components themselves. Passivhaus takes this further than other building standards in providing a continuous airtight layer to almost eliminates these losses and provides fresh filtered air using Mechanical Ventilation with Heat Recovery (MVHR), bringing with it excellent indoor air quality. We use the latest energy modelling analysis, a deep understanding of building physics and high-quality robust details, to adhere to the rigorous scientific approach throughout the design and construction stages.
The Passivhaus Institute's retrofit standard, Enerphit, is tailored to the challenges of achieving ultra-low energy use in existing buildings, whilst acknowledging the constraints of its predefined form existing construction types.
A well insulated and airtight building significantly reduces unintended heat loss through the building components themselves. Passivhaus takes this further than other building standards in providing a continuous airtight layer to almost eliminates these losses and provides fresh filtered air using Mechanical Ventilation with Heat Recovery (MVHR), bringing with it excellent indoor air quality. We use the latest energy modelling analysis, a deep understanding of building physics and high-quality robust details, to adhere to the rigorous scientific approach throughout the design and construction stages.
The Passivhaus Institute's retrofit standard, Enerphit, is tailored to the challenges of achieving ultra-low energy use in existing buildings, whilst acknowledging the constraints of its predefined form existing construction types.
Environmental Design Tools
To analyse the environmental design throughout the design process we use the Passivhaus Planning Package (PHPP), an energy and design optimisation tool that calculates the expected energy flows of buildings. This is regularly updated and refined and has had its accuracy validated through decades of testing (with comparison of simulated data to the as-built monitored buildings ref) and forms the core of the information required for the Certification of a Passivhaus or Enerphit building. We also use the Passivhaus 3D modelling tool, designPH, to further refine the accuracy of our designs within the local context. For those more technically minded, or just interested, this level of analysis can be at the forefront of our conversations throughout the design process. For those wanting to focus on design, you can have the confidence that we will be looking to optimise the sustainability of your project (behind the scenes) throughout the design process.
Maximum Annual Heating Demand is 15 KWh
of energy used per m2 of floor area per year.
or
Peak Heating Load of 10W per m2
of floor area on the coldest day of the year.
---
Airtightness of 0.6 air changes
per hour at Test Pressure (50Pa)
---
< 10% Overheating
(we aim for no overheating)
Eliminating The Performance Gap
Passivhaus & Enerphit certification effectively eliminates the problems of the performance gap that hounds most standard building projects, where the as-built construction does not meet with the designed energy aspirations. The average UK home (built between 2008 and 2016) is likely to use around 40% more energy than predicted, with heating demand sometimes 2 to 3 times greater (Passivhaus Trust). To put this in context, a representative 3-4 bedroom house (MHCLG), built to meet current UK building regulations, would likely require 80-140 kWh/m2 of heating per year (DECC), rather than a certified Passivhaus which would use less than 15 kWh/m2 of heating each year.
The scientifically backed methods of Passivhaus Certification require the building to be physically tested during construction and on completion to ensure the real world performance meets the design intentions. This differs significantly from UK Building Regulations methodology which doesn't typically test the completed building.
With over 25,000 Passivhaus Certified buildings around the world (see map), and over 1000 in the UK alone, Passivhaus Certification is an increasingly sought after low energy building standard for those who value quality and consistency.
The scientifically backed methods of Passivhaus Certification require the building to be physically tested during construction and on completion to ensure the real world performance meets the design intentions. This differs significantly from UK Building Regulations methodology which doesn't typically test the completed building.
With over 25,000 Passivhaus Certified buildings around the world (see map), and over 1000 in the UK alone, Passivhaus Certification is an increasingly sought after low energy building standard for those who value quality and consistency.
Holistic Approach to Design
While the Passivhaus Institute's standards takes care of the energy demands, thermal comfort and air quality, we understand there is so much more to design...the days of the ultra-low energy buildings being conceived as boring boxes with small unopenable windows are long gone!
Our approach to design typically starts with a review of how you are likely to use the spaces and what suits your lifestyle. We always aim to keep your character and personality at the heart of your project whilst being responsive to the surrounding context and economic climate. Careful consideration is given to the material choices both internally and externally, as well as those little details which really make the design sing. We see minimalising the building's energy impact as one part of the puzzle and look to add value by bringing in our expertise in natural materials, alternative construction systems, lowering embodied carbon and ensuring we still create spaces that are relaxing, fun and personal.
Our approach to design typically starts with a review of how you are likely to use the spaces and what suits your lifestyle. We always aim to keep your character and personality at the heart of your project whilst being responsive to the surrounding context and economic climate. Careful consideration is given to the material choices both internally and externally, as well as those little details which really make the design sing. We see minimalising the building's energy impact as one part of the puzzle and look to add value by bringing in our expertise in natural materials, alternative construction systems, lowering embodied carbon and ensuring we still create spaces that are relaxing, fun and personal.
Maximum Annual Heating Demand is 25 KWh
of energy used per m2 of floor area per year.
or
Passivhaus Certified Components
to established minimum standards
---
Airtightness of 1 air changes
per hour at Test Pressure (50Pa)
---
< 10% Overheating
(we aim for no overheating)
of energy used per m2 of floor area per year.
or
Passivhaus Certified Components
to established minimum standards
---
Airtightness of 1 air changes
per hour at Test Pressure (50Pa)
---
< 10% Overheating
(we aim for no overheating)
Enerphit Retrofit Standard
The Passivhaus Institute recognises the necessity and challenges of improving existing buildings with their Enerphit retrofit standard. This variation of the Passivhaus standard acknowledges the potential limitations of working with an existing building and so has less stringent (although still significant!) airtightness and energy requirements. Taking a building to Enerphit requires a strong desire from the client to optimise their home, as well as significant expertise from the designer, which our team can offer. The works can be phased over a number of years, using an Enerphit Retrofit Plan, to meet with your constraints (whether that's budget or the need to continue living in the space while the work is undertaken).
To put an Enerphit retrofit into context, we have found that a, fairly typical, air-leaky early-1900's terraced house might change its internal air volume up to 4 times per hour and when that air leaves the building through tiny gaps in the construction, under skirting boards and around windows etc, it takes with it a significant amount of the building’s heat (all of which you have likely paid for in your energy bills). Using the 'blower-door' test-pressure (50 Pa – equivalent to a very strong storm), this equates to about 20 air changes per hour, while an Enerphit retrofit must meet just 1 air change per hour at this pressure.
To put an Enerphit retrofit into context, we have found that a, fairly typical, air-leaky early-1900's terraced house might change its internal air volume up to 4 times per hour and when that air leaves the building through tiny gaps in the construction, under skirting boards and around windows etc, it takes with it a significant amount of the building’s heat (all of which you have likely paid for in your energy bills). Using the 'blower-door' test-pressure (50 Pa – equivalent to a very strong storm), this equates to about 20 air changes per hour, while an Enerphit retrofit must meet just 1 air change per hour at this pressure.