Passivhaus-Inspired 1980s Home Retrofit, Gunnell Close, Milton

Passivhaus-Inspired 1980s Home Retrofit, Gunnell Close, Milton

Sun 26 Oct 2025, – Sat 8 Nov 2025, Various

Meet your hosts, Spyros and Apostolos

When we moved, we wanted a larger home that would lend itself to improvements and in particular energy efficiency retrofits. We bought this late 1980s detached home in June 2024 and immediately embarked on a full deep retrofit. We both like to spend time at home, both with friends and just ourselves, and having both worked extensively from home – even pre-pandemic – we placed high priority on comfort, air quality, and energy efficiency.  

While drawing on professional knowledge, we also found value in practical conversations with tradespeople and real-world examples from the Passivhaus community,” says Apostolos.  

Passivhaus is a globally recognised design standard that ensures exceptional comfort and indoor air quality, while dramatically reducing a building’s energy consumption for heating and cooling. As Apostolos is an architect and a Certified Passivhaus Designer, the retrofit was designed using the Passivhaus principles and modelled using the Passivhaus Planning Package (PHPP). Since completing the work, the air quality is markedly better, and the house is noticeably quieter. We are more aware of actively managing solar gains, especially during heat spells, and are slowly implementing smart controls for lighting, heating, ventilation and security. The switch to all-electric systems (via ASHP) and inclusion of MVHR will significantly enhance efficiency while increasing comfort. We feel proud of the home’s potential having taken great care to ensure the plans all came up to standard and we look forward to further tweaks and improvements.  

Key features of this home 

  • External wall insulation 
  • Floor insulation using vacuum insulating panels
  • Loft insulation with mineral wool  
  • Airtightness enhancements across building fabric  
  • Triple glazed timber/ aluminium composite windows  
  • MVHR system with rigid metal ductwork  
  • Air source heat pump installation with low-temperature radiators  
  • Cooling via fan coil unit (connected to ASHP)  
  • Smart LED lighting set up with home automation infrastructure  
  • Infrastructure for future PV, battery storage and EV charging  
  • Internal venetian blinds for solar control  
  • Smart electricity and water meters  
  • Rewilded garden for biodiversity and stormwater resilience  

Our hosts’ top tips  

  • Don’t come with answers – bring questions to your contractors.  
  • Design thoroughly but keep contingencies in mind.  
  • Achieving airtightness is harder than it seems. Prepare accordingly. 

Download PDF case study with details and links.

Book now:

Sun 26th Oct 11 am, 1 pm & 3 pm

Sat 8th Nov 11 am, 1 pm & 3 pm

 

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