Sustainable Properties
‘Sustainably’ and its variants has become a prefix to many words that a few years ago would have sat within a sentence without such bedfellows. Think ‘sourced’, ‘grown’ ad infinitum. These days it’s hard not to land upon a webpage to find such adjectives qualified by claims that aspire to the zeitgeist of our age – notably ones that reassure the would-be purchaser that the service or product they are about to buy is eco/planet/environmentally friendly; take your pick. Not wishing to name names, it would be churlish to admonish those companies here, but a bit of research often reveals a certain amount of greenwashing has taken place, especially when it comes to sustainable properties.
Of course, there are those who haven’t just hitched a ride on the bandwagon. Without wishing to sound too boastful we believe we are one such company. We are ARCO2. Known for our commitment to reducing environmental impact from the outset, we incorporate sustainable materials, energy-efficient technologies and ecological principles into all of our projects. This blog explores two exemplary case studies of our work: Keynvor in Mawgan Porth and No.5 Gwithian Towans, highlighting our approach to designing sustainable properties along with the benefits.
Case Study One: Keynvor, Mawgan Porth, Cornwall
Keynvor is a low-energy, sustainable dwelling inspired by Passivhaus principles, that was designed to replace an outdated holiday let from the 1970s. The original structure had undergone multiple refurbishments and extensions, resulting in a disjointed and inefficient use of the site. Situated on a triangular plot along Tredragon Road, just 200 meters from the coastline, the site was ripe for redevelopment to better utilise its potential and scenic views.
Client Brief
The clients’ envisioned a sustainable home that maximised natural light and views, while providing private, introspective spaces. They sought to enhance biodiversity, replacing the existing lawn with diverse planting that would create a seamless indoor to outdoor relationship. The new design needed to blend with the local architecture while introducing contemporary elements, and to respect and improve views for neighbouring properties. Sustainability was paramount, aiming for minimal energy consumption through a fabric-first approach supplemented by renewable technologies.
Design Concept
Our design for Keynvor was grounded in a comprehensive site analysis and strategic layout:
Entrance and Views: The layout prioritises entrance views from the east and pedestrian-scale views from the west, ensuring a balance of public and private spaces.
Massing and Scale: The building’s massing respects the surrounding area, with the first floor oriented east-west to frame sea views with the ground floor stretching north-south to utilise the triangular plot efficiently.
Reverse Level Living: Living spaces are on the upper floor to capitalise on the views, with a clear hierarchy of open and private spaces.
Solar Shading: Strategic fenestration and overhangs, along with flexible shading shutters, mitigate solar gain while preserving views.
Robust Materials: The use of durable, low-maintenance materials like slate, timber cladding and zinc enhance the building’s resilience and aesthetic harmony with the environment.
Sedum Roofs: Extensive sedum roofs reduce rainwater runoff, enhance biodiversity and visually integrate the building into the landscape.
VR Statement and Design Technologies: We utilised advanced design technologies, including 3D rendering and virtual reality (VR), to engage clients in the design process. This allowed for real-time detailing and efficient resolution of design elements, ensuring a seamless transition from concept to construction.
Construction Overview
Keynvor’s construction employed sustainable practices and materials:
Foundation and Flooring: A reinforced concrete raft foundation with high-performance insulation and underfloor heating ensured energy efficiency.
Walls and Insulation: Double timber frames with recycled newspaper insulation and mineral wool created a highly efficient and airtight structure.
Roof and Timber: Engineered I-joists and sustainably sourced timber minimised cold bridging and the environmental impact.
Construction Materials
The choice of materials reflected our commitment to sustainability:
Warmcel Insulation: Made from recycled newspapers, Warmcel has a low global warming potential and excellent thermal properties.
Glass Mineral Wool: ECOSE® Technology insulation with no added formaldehyde, ensured healthy indoor air quality.
Engineered Timber: FSC and PEFC certified I-joists and timber products offered strength, sustainability and minimal environmental impact.
Green Roof: A biodiverse sedum roof supports local flora and fauna while improving rainwater management.
High-Spec Windows and Rainwater Goods: Triple-glazed aluminium windows and zinc rainwater systems ensure durability in the coastal environment.
Performance
Keynvor achieves exemplary energy performance with Passivhaus-level insulation and airtightness, supplemented by renewable energy systems like PV panels and an air source heat pump. This results in consistent comfort levels with minimal energy input, demonstrating our fabric-first approach.
Landscaping, Ecology, and Biodiversity
The landscaping plan enhances biodiversity with native plants and interconnected spaces. It creates a calm environment that blends with the built-up surroundings, encouraging stillness and interaction with nature.
Challenges and Value
The project faced challenges like Covid-related disruptions and rising material costs but managed to deliver exceptional value. With a final build cost of £1.7M and an estimated market value of £5M, Keynvor exemplifies profitable sustainable development.
Case Study Two: No.5 Gwithian Towans
No.5 Gwithian Towans is a new, modest three-bedroom home replacing a 1950s bungalow. Located near an Area of Outstanding Natural Beauty and a Site of Special Scientific Interest, the site demanded a sensitive and sustainable approach.
Client Brief
The new house needed to be energy-efficient, comfortable, and resilient to the harsh coastal climate. The design had to comply with the stringent Gwithian and Gwinear Neighbourhood Plan which emphasised an adherence to ecological and community considerations.
Design Concept
The design we settled upon subtly integrated with the dune landscape, offering seaward views without compromising privacy. Its simple form and modest scale, combined with high-quality detailing and durable materials, ensure longevity and minimal maintenance.
Ecology and Biodiversity
The driveways feature porous surfaces and the garage gable incorporates a bat home. A new Cornish hedge, extensive garden planting and a living roof enhance the site’s ecological value, thus supporting local biodiversity.
Communities and Local Economy
The design adheres to the Gwithian Towans Design Guide, involving local architects and builders to support the community and economy. The project utilised local materials and labour, ensuring that the economic benefits remained within the region.
Maintenance and Health & Wellbeing
Durable materials like extra-thick roof slates, aluclad timber windows and natural timber cladding ensure longevity and low maintenance. Passive house principles guide the design, providing excellent indoor air quality and minimal energy use, enhancing occupant health and comfort.
Waste and Pollution
The project minimised waste through efficient construction methods and careful material selection. FSC-certified timber, low VOC finishes and recyclable materials reduced environmental impact. The demolition of the old house was managed to ensure safe disposal of hazardous materials too.
Energy and Water Conservation
A fabric-first approach with natural materials, excellent airtightness and MVHR ensured energy efficiency and occupant health. On-site water management systems treat and soak away all foul and surface water, promoting water conservation.
Materials
The design prioritises natural, unprocessed materials for minimal environmental impact and ease of disposal or reuse. Timber and its derivatives, high-value recyclable materials and minimal use of plastics characterise the sustainable material strategy.
Sustainable Properties Conclusion
These projects (two amongst many), Keynvor and No.5 Gwithian Towans, illustrate our commitment to sustainable architecture. By integrating advanced technologies, using eco-friendly materials and adopting a fabric-first approach, ARCO2 creates buildings that are not only environmentally responsible but also enhance the well-being of their occupants. These case studies highlight the potential for sustainable development to achieve economic viability and aesthetic excellence, setting a benchmark for future projects in Cornwall and beyond.
