EBRON HA MOR

Area: 232m² (each of the two dwelling)

Procurement: Westhaven Developments Ltd. In-house Project Management & Development company

As Built SAP: 87/88B Environmental Impact: 89B With 4kW Solar Panels: 92/93A

Construction Stage Air Pressure Test: 1.0 m³.h^-1.m^-2@50 Pa

LABC: Cornwall Council (Plan Check & Inspections)

Ebron Ha Mor reimagines two uninspired dormer bungalows into refined, sustainable coastal dwellings that harmonise with their dramatic clifftop setting. Designed as architectural siblings, the homes share a contemporary beach-inspired language while retaining individuality. We worked within the constraints of existing planning consent, pushing the boundaries of non-material amendments to deliver high-performance, low-energy homes with SAP ratings up to 93A and airtightness of 1.0 m³/h/m² @ 50Pa.

Built using the innovative Cornish R-Wall ICF system and locally sourced low-carbon concrete, the homes feature engineered timber joists, MVHR, ASHP, and sedum-roofed garages. VR design enabled precise spatial planning and privacy optimisation. With panoramic sea views, solar shading, and tranquil interiors, Ebron Ha Mor exemplifies how thoughtful design can elevate constrained planning into site-responsive, future-proof architecture.

The client brief called for two homes, each with a Gross Internal Floor Area of 218 and 233 square metres, designed as complementary “brother and sister” buildings. While sharing a consistent architectural language, each was to retain its own unique character. The design needed to be simple, well detailed, and practical to construct, using natural, robust, and low-maintenance materials. The aesthetic was to be contemporary yet sympathetic to its coastal setting, reflecting a relaxed beachside feel. Provision for a car port or garage was required, along with layouts that maximise the surrounding views.

• GIFA 218 & 233 sq. m
• Consider buildings as ‘brother and sister’, similar language but unique
• Design to be simple, well detailed and buildable
• Natural materials, robust and low maintenance
• Contemporary but sympathetic with beach feel
• Car port or garage
• Make the most of views

The design intention of the proposals was to offer progressive, but restful architecture that integrates respectfully within the coastal setting. The prominent location of the site, amongst a plethora of architectural styles and building scales, offers an opportunity to provide an encouraging and introverted concept, with an emphasis on a restful design language and fenestration. Design cues have therefore been taken from the local built vernacular; including size, form and the type of materials appropriate to the location both in terms of longevity and architectural aesthetic.  The brief evolved into key considerations for the concept, which included:

• Reducing the visual impact of the development on the town of Mawgan Porth. Achieved through rotation of the proposals, reduction in amount of glazing on south facing elevations and a sensitive landscape proposal
• Creating a design proposal with the planet in mind. The introduction of solar shading will lead to far more energy efficient dwellings and improved thermal comfort, avoiding the certain overheating with the existing design
• Improving privacy. Carefully curated views through calculated positioning of glazing, benefitting from the surrounding beauty and reducing the likelihood of opportunities to overlook neighbours via Virtual Reality (VR) design.
• An open plan lounge kitchen and dining on the GF taking advantage of the views with free flow into a sensitive and carefully designed garden with hard and soft areas in which to extend the living areas creating an inside/outside feel. The landscaping provides a seamless transition between the revised proposals and their surroundings
• An accessible GF double bedroom with en-suite and private garden views sheltered from the prevailing winds
• A GF en-suite bedroom accommodating bunk beds and a place for children to thrive with a large panoramic low level window seat from which to admire the panoramic coastal views
• A dedicated plant room with utility space and cloakroom
• 2 no. 1^st floor double bedrooms with en-suites, the master with an area to sit leading out onto a balcony which provides solar shading to the lounge sliding doors below and also a dressing room. The other bedroom features a window seat and storage areas
• Creating a 1^st floor dual aspect snug area with balcony access and views towards the church over the feature stairwell when sitting
• Incorporating a feature cantilevered staircase
• Reducing the amount of stone and increasing the amount of zinc to create a modern interpretation of vernacular design. Subtle design differences will help to portray a brother and sister relationship.
• New interventions beyond the mass of the original consent such as dormers, solar shading and entrance porches to be clearly defined with copper to work in symbiosis with the zinc and to soften with a natural patina
• Rationalize the excessive glazing and rooflights to create balance and order. The new proposals have fewer, better architecturally proportioned windows to suit the revised layout and their surroundings.  The proposed fenestration achieves previously un-accessed views of the surrounding landscape, which is further aided by the revised orientation.
• As the building forms are fairly simple and traditional, we decided to emphasise the detailing to ensure a clean, crisp modern finish, one example of this include how the roof zinc and wall zinc meet with a secret gutter and hidden downpipes
• Create a beach vibe with timber to add warmth, lime washes, curves; a light bright inside to contrast with the dark exterior which visually blends into the landscape
• Detached garages with sedum roofs and charred cladding via a separate planning application so as not to jeopardise the non-material amendment (NMA)
• Landscape which creates shelter from the wind whilst retaining views, harmoniously screening the garages

The proposal has been conceived around the need to provide sustainable homes which embrace high levels of insulation with airtight construction, an air source heat pump for all heating and hot water, MVHR, passive stack and cross purge ventilation and careful selection of materials to minimise the carbon footprint.

Due to the very exposed nature of the site (often seeing 80mph winds) the walls and ground floor were constructed using a newly developed Cornish ICF system known as R-Wall.  The insulation is waterproof being XPS insulation and provides extremely good U-Values.  Insulating underneath the slab ensured thermal bridge free construction and continuity of the concrete core not only providing strength but exceptional levels of airtightness.  The concrete was locally manufactured using secondary aggregate from the clay industry, helping to minimise the carbon content of the concrete.  The slab accommodated the underfloor heating pipes and provided the level sub floor which meant that a screed was not necessary, helping to save cost/materials and carbon.  A self-levelling compound was required underneath the final engineered oak floor finish.  The roof consists of engineered I joists which use less timber, span further than solid timber and have minimal cold bridging.  Due to being predominantly a masonry fabric there is plenty of thermal mass to create a thermal fly wheel affect and smooth out temperature spikes. Acoustically the house provides calm amongst the storms, offering peace and tranquillity.

The basic principles employed during the design, specification and construction is to ensure that the building has low embodied CO₂ content. Materials were selected that have not required a large amount of energy in their sourcing, processing or transportation. The solutions include:

1. R-Wall ICF external walls and insulated ground floor: Ravatherm XPS high performance extruded homogeneous polystyrene closed cell insulation provides excellent thermal insulation, is waterproof with negligible moisture uptake with a high compressive strength.  The concrete core utilises secondary aggregates from the nearby clay industry which helps to minimise the carbon content.
2. Floor membrane: Visqueen Eco Membrane: Manufactured from 100% post-use polyethylene, diverting more waste from landfill.
3. I-Joists: Engineered timber joists made from small sections of timber and timber by products (see below). They offer many design and performance advantages over conventional structural products including a composition which resists shrinking and warping, an excellent strength to weight ratio straight and uniform dimensions. The joists also have FSC & PEFC Accreditation & Labelling, Life Cycle Assessment and ISO 14001:2004 Environment Management System.
4. Timber for internal partitions & joists: recognised as one of the most sustainable building materials, all timber has been specified carefully ensuring that the chain of custody is clear.  This protects against irresponsible sourcing and irreversible damage to delicate ecosystems. Where possible, we advocate the use of European timber (FSC & PEFC) timber such as shou sugi ban (charred) larch which was used for cladding.
5. Warmcel recycled newspaper insulation: Warmcel is a natureplus® certified product. This is a standard for products that meet the highest standards from raw material sourcing / extraction, to low emissions and clean production methods.  Warmcel is manufactured from recycled newspapers, these are collected from offices, schools, overruns from printing companies and kerbside collections. The manufacturing process uses very little energy, the combination of the cellulose fibre properties and its specific manufacturing process gives Warmcel an extremely low Global Warming Potential of -1.5 Kg Co₂/m².  The CO₂ sequestered within Warmcel is then locked into your building and is actually less than the CO₂ produced in the manufacturing process.  Unlike other insulations, Warmcel is an inert material with no off-gassing of Volatile Organic Compounds, making it the best insulation for a truly healthy home.
6. Timber by-products: such as the bitumen impregnated fibreboard to the roof (Bitroc), orientated strand board (OSB), and hardboard (air tightness layer) have also been incorporated in order to utilise further waste products.  Additionally, these products have lower chemical content in terms of adhesives and binders than composite materials such as chipboard and medium density fibreboard, both of which have reported harmful binders which can cause a health hazard when working with the materials.
7. Glulam Beams: Small sections of timber from sustainable sources glue laminated to provide a larger structural grade timber.  Used for ridge beam and stair trimmers.
8. Earthwool: insulation to acoustic walls and floors (where breathability is not required).  A+ Generic BRE Green Guide rating.  Made using recycled materials.  Made from rapidly renewable organic materials. No added formaldehyde binder.  No added dyes.  Up to 70% less embodied energy and recyclable.
9. Roof membranes: Designed as a breathing shell (vapour permeable) which is not susceptible to condensation build up and significantly reduces the risk of associated respiratory illness.  As it breathes the structural frame is less prone to decay and offers greater longevity
10. External Joinery: High specification triple glazed windows were specified to help reduce heat loss.  Velfac aluminium clad timber were chosen due to the high efficiency, sustainability, minimal sight lines and minimal maintenance due to being located close to the sea. All timber is FSC certified, have a lifespan of 40 years 2/3 of the aluminium is manufactured using renewable energy and approx. 40% come from recycled sources.  Each unit is designed to be disassembled and re-used at the end of its life cycle.
11. Garage Green roof: consist of varieties of sedum that flower throughout the year and promotes a range of wildlife as well as looking spectacular year-round but especially in late spring during the main flowering season. This roof also assists the drainage of the building by slowing down/holding up the run off of water from the roof prior to entering the drainage system.
12. Rainwater goods: Zinc rainwater goods were selected because of their quality, durability, minimal maintenance, and recyclability.
13. Natural Stone: Quarried locally supporting local economy and minimising transportation/CO₂.

A Phase 1 Ecology Survey was undertaken to establish if there was evidence of bats, none were found during the visual appraisal and the emergence survey.  No bats were found during demolition.

The biodiverse sedum green roofs and sensitive planting scheme incorporating large stone hedgerow (stones excavated from the site) provides the perfect habitat for a plethora of wildlife including invertebrates, amphibians, insects and small mammals (a wildlife superhighway). The adjoining fields have also been be managed to become wildflower meadows.  A number of Green & Blue Beeposts can also be found around the site.  Overall, there is significant biodiversity enhancement/gain.

The house exceeds the minimum Passive House U-Values for all fabric elements with the exception of the triple glazing whilst narrowly misses the target.  The properties have respectable SAP/EPC result and great air pressure test result, which just missed the stringent passive house standard of 0.6 by 0.4.  Given that this is the developers first low energy project and first project using the R-Wall system we feel that this is an extremely good result, especially considering the evolution of this project and how it has been transformed into a project striving for and achieving excellence. The house requires very minimal heating throughout the year and importantly do not overheat in the summer, eliminating any requirements for cooling.

This project was the developers first high-end low energy project and the first using these construction methods and building services systems.  Although there was a learning curve they firmly enjoyed the challenge.  Constructing similar sustainable low energy projects is now their business model and we are extremely pleased to be continuing this relationship working together on further exciting bespoke site-specific properties within the locality.