Describing Howgate Close as eco-homes is to understate its performance. Most notable are these five 2-bed homes and four 1-bed homes, all operate beyond zero carbon.  They are on the outskirts of Eakring a rural village near Southwell/Ollerton in Nottinghamshire.

Design Origin Of Howgate’s Eco Homes

1. Eco Homes Provide An Acceptable Return On Investment (ROI)
2.  

Hockerton Housing Project (HHP)  design for the Eakring Eco Homes project, uses the design principles applied at HHP.  The HHP’s Architects, are Professors Brenda and Robert Vale, The Vale’s.  Check out HHP building standards and  FAQ

These design principles were first published in The Vale’s 1975 book, ‘The Auton

1. omous House’, and implemented at their former Southwell home, ‘The New Autonomous House’. It’s worth noting, that over 40 years later, The Vale’s design principles have been applied less than 7 miles from The Vale’s former home. To their credit, on July 27th, 1994, their Southwell home became the UK’s first dwelling to export photovoltaic-generated renewable energy to the National Grid.

“What makes the Eakring (Eco Homes) project truly exceptional is the unique combined experience of the HHP design team. A team that has twenty-four years of designing, constructing, maintaining, and servicing the UK’s largest collection of autonomous earth-sheltered buildings.”

Final Assessment Report
Compliance with Condition 12

Newark & Sherwood District Council
July 2019

Prior to construction, Dr Parsons undertook technical adjustments to the approved design raising the EPC Rating from a SAP Rating of 84 to 143.

Design Principles

Introduced in detail below, are Howgate’s design principles. Also provided is third-party verification of their performance via the Standard Assessment Procedure (SAP).

Passive Solar Design Techniques

Intrinsic to the buildings performance, is the utilisation of the passive solar design principles pioneered by The Vale’s.  HHP’s application of these techniques include;

1. Southerly orientation
2. High thermal mass superstructure
3. Super-insulated envelope
4. Renewable energy

Further specification enhancements at Howgate Close include;

• Solid external walls (no cavities)
• Floating slab (no foundations)
• Contiguous external insulated envelope (no cold bridging)
• Triple glazing
• Reduced reliance on mechanical ventilation
• Back-up electric underfloor heating
• Externally located window and door jambs (improved Psi values)
• Hot water demand at source (no stored hot water)

For the record, Dr. Parsons first conceived the idea of his replicable development solution in 2015. His intention was to resolve several local issues that have both national and global significance. He observed, a shortage of local affordable rural homes and a progressively diminishing bio-diversity in the surrounding Nottinghamshire countryside.

Eradication of the risk of fuel poverty was a priority for Dr Parsons while nurturing a conducive neighbourhood that mitigates greenhouse gas emissions.  He succeeded in his aims. Additional aspects of the model comprise, taking 10 acres out of intensive arable farming, constructs nine homes for rent and installs 60KW’s of solar panels (142 panels) He’s also planting 10,000 trees and hedgerow, creating wildflower meadows, scrubland, and a wetland.

“..an opportunity to address some of society’s most pressing issues: rural housing shortages, climate change, soil restoration, carbon sequestration, biodiversity, water management, and community cohesiveness.”

Dr. Parsons
(as reported in CLA Magazine)

Furthermore, this Case Study demonstrates these eco homes are a viable alternative to conventional social housing and affordable homes. Equally important, They also deliver a new level of energy efficiency and carbon mitigation associated with Eco Homes or Zero Carbon Homes.

“Howgate Close epitomises the aims of the Councils De-Carbonisation Plan and would encourage more of the same.”

John Robinson
(CEO Newark & Sherwood District Council)
2023

In evaluating the viability of Dr. Parsons model, it’s useful to refer to Howgate’s Return On Investment (ROI). Usefully, the model’s efficiency of investment is assessed on several levels; economic, carbon emissions, social and community integration.

First, at an economic level, Howgate achieves a 5% ROI with a 20-year payback period (Amortisation) using conventional financial performance measures.

Second, carbon emissions provide another performance metric with national and global implications. According to the nine Energy Performance Certificates (EPC’s), the homes collectively mitigate 16 tonnes of carbon emissions each year from their renewable energy generation. Adding a further 9 tonnes annually of carbon sequestration annually is the re-wilding of 9 acres.   Consequently, the site’s Biodiversity Net Gain (BNG) will likely exceed Natural England’s soon-to-be mandatory minimum 10% benchmark.

Furthermore, full financial benefits of the 60KW’s of roof-mounted photovoltaics are given to Howgate’s residents. Consequently, first 10 months’ energy bills, average less than £1 per day across all nine homes. 54pence/day as of 12^th July 2023.

It should be noted that Dr Parsons investment returns at Howgate Close compare favourably to their financial cost.

Luke Jackson  Eagle Building Specialists– builder of Howgate Close

It was interesting to catch up with Luke to see how he found the challenge of the build we will be doing a more in-depth blog with Luke next, so this is just a taster.

“The general technology wasn’t a challenge as I was familiar with Hockerton Housing Project, it excited me.  The lads working for me were far more sceptical it wasn’t until a winters day when the buildings were airtight that they started to appreciate how warm they were.  In the end the proof was in the pudding as they say.   In all honesty even I didn’t quite realise how efficient they would be!”