Ian Chalk Architects Wins Approval for Perranporth Passivhaus

Key facts

• Cornwall Council has approved The Watch House, a 535-square-metre coastal Passivhaus at Droskyn Point in Perranporth.
• The project replaces two neighbouring detached houses, one built eight years ago and another recently purchased by the clients.
• The building is designed for three generations, featuring level internal access routes for young children and grandparents.
• The scheme is net-positive, generating 67 per cent more energy than it consumes using solar panels and ground source heat pumps.
• Construction is scheduled to begin in 2027, with completion planned for 2028 following a 15-month build programme.

Cornwall Council has granted planning permission for The Watch House, a bespoke multi-generational Passivhaus dwelling designed by Ian Chalk Architects on a cliff edge in Perranporth. The approved scheme replaces two existing properties at Droskyn Point with an energy net-positive coastal home providing 535 square metres of internal floorspace.

Demolition and consolidation at Droskyn Point

The planning decision authorises the clearance of two neighbouring detached houses situated on a steeply sloping cliffside plot overlooking Perranporth beach. As first reported by Architects' Journal, the application consolidates two adjoining plots into a unified family holding. One of the existing houses was built by the private clients eight years ago as their family residence, while the second property on the adjacent parcel was acquired more recently to allow the development of a comprehensive single-dwelling scheme.

The replacement building will combine the residential footprints into a single house planned specifically for three generations of the same family. Cornwall Council approved the application without referral to committee, establishing consent for a layout that provides level circulation routes and independent wings capable of accommodating young children alongside grandparents.

Planning context on the north Cornwall coast

The site occupies a prominent cliff-top position subject to sensitive landscape policies and exposed maritime conditions. Proposals for replacement dwellings on coastal headlands in Cornwall require careful justification regarding structural massing, visual impact from public beaches, and shoreline stability. The sloping topography required a bespoke stepped section to ground the building into the hillside rather than projecting aggressively above the skyline.

To address local landscape and historical sensitivities, heritage consultancy Silverlake and landscape architecture practice Mei Loci were brought into the design team during the pre-application phase. The resulting proposal integrates native flora and a terraced bank to stabilise the surrounding ground, similar to the environmental care required on exposed northern waterfronts seen in projects like the Hyde + Hyde upgrade on the Northumberland coast. Cornwall's local planning policies support high-performance sustainable buildings where design quality minimises visual intrusion on coastal headlands.

Dual-wing layout and environmental specification

The Watch House is split into two primary volumes arranged around a central sheltered courtyard. The northern wing faces the Atlantic Ocean, framing direct coastal views over the beach below. This block houses the primary living areas, arranged around a double-height open-plan kitchen and living space, alongside the principal bedroom suite. Interior schemes for these shared spaces are being designed by RA Studio. The eastern wing contains the children's bedrooms and a ground-floor guest suite positioned to offer step-free access for visiting grandparents.

A central courtyard buffers the domestic spaces against prevailing Atlantic weather. This enclosure contains an integrated kitchen garden and an all-season greenhouse, creating a wind-sheltered outdoor environment for food growing and family use. External landscaping stepping down from the house includes a raised terrace, newly planted native trees, and indigenous cliffside vegetation.

The construction specification combines traditional regional materials with heavy thermal mass and natural interior finishes. Load-bearing masonry walls are clad externally in local Cornish stone, while the primary structural frame incorporates exposed timber members throughout the interior. Walls and ceilings are lined with natural clay plasters to regulate indoor relative humidity, complemented by heated polished concrete floor slabs.

Engineered to low energy & Passivhaus performance standards, the building fabric features continuous mechanical ventilation with heat recovery (MVHR), extensive airtightness detailing, and triple glazing. Space heating and hot water are supplied by ground source heat pumps connected to a ground loop array. An extensive photovoltaic panel installation is designed to generate 67 per cent more electricity than the house consumes over an operational year, resulting in net-negative carbon emissions before household electric vehicle charging points draw down the surplus generation. A extensive sedum green roof spans the structure to attenuate rainfall and encourage cliff-top biodiversity.

Design response to severe Atlantic conditions

Ian Chalk, founder and director of Ian Chalk Architects, noted that the exposed headland location required an architecture capable of resisting fierce maritime weather systems while remaining open to summer light and coastal breezes. Chalk described the completed scheme as a "richly crafted, robust, sustainable and distinctly local family home" developed to withstand driving rainfall and gale-force northerly winds.

The architects emphasised that the dual-wing composition directly responds to the daily domestic rhythms of an extended family. By separating the primary shared rooms from the secondary bedroom wing, the internal arrangement enables multiple age groups to convene in the double-height social spaces or retreat to quieter private quarters. Technical input from services engineer Inside Outside Engineers and structural engineer Momentum ensured the deep overhangs, heavy stone walls, and thermal mass perform consistently across disparate seasons.

Construction programme and delivery timeline

Following the grant of planning consent by Cornwall Council, the project team will advance detailed construction documentation and technical specifications. Work on site is scheduled to commence in 2027, with building works governed by a 15-month construction contract.

Completion and handover are scheduled for 2028. Project management and CDM coordination are being managed by Crabb Consulting. Sweco has been appointed as the approved building inspector, with cost consultancy and quantity surveying services delivered by WG Weller & Son.

Timeline

1. 2018Clients complete construction of their first home on Droskyn Point.
2. October 2026Cornwall Council approves planning application for replacement Passivhaus.
3. 2027Construction work scheduled to begin on site at Perranporth.
4. 2028Targeted practical completion following a 15-month building programme.

Why this matters

The approval demonstrates how sensitive coastal headlands in England can accommodate multi-generational replacement dwellings when energy performance far exceeds standard building regulations. By targeting Passivhaus performance and net-positive generation on an exposed cliff, the project provides a technical precedent for replacing fragmented low-density housing with durable, regionally clad architecture that generates surplus clean energy.

Questions answered

where is the watch house located

The Watch House is located on the cliff top at Droskyn Point in Perranporth, north Cornwall, overlooking Perranporth beach.

who designed the perranporth passivhaus

The replacement dwelling was designed by Ian Chalk Architects, with interiors designed by RA Studio and landscape architecture by Mei Loci.

what is being replaced at droskyn point

The project demolishes two adjacent houses: one constructed by the owners eight years ago and an adjoining neighbouring property acquired recently.

how energy efficient is the watch house

Built to Passivhaus specifications, the house is net positive, generating 67 per cent more energy than it consumes via solar PV and ground source heat pumps.

what materials are used in the watch house

The building uses local Cornish stone wall cladding, an internal exposed timber structure, clay plaster finishes, and heated concrete floors under a green roof.

when will construction start on the watch house

Construction on site is scheduled to begin in 2027, with final completion expected in 2028 after a 15-month build.

Source: originally reported by Architects' Journal.