Robin Lee Architecture extends arts and crafts villa in Hampshire conservation area

What was the brief for this project?

The brief was to extend a detached arts and crafts-era villa within a conservation area. We developed a substantial side extension, intended to sit within the streetscape of this historic quarter of Petersfield in Hampshire – at once contemporary and contextually sensitive.

In addition, we proposed a rear extension that could mediate in scale and character between the villa’s relatively grand rear elevation and a private garden setting. For the latter, we developed the notion of a Victorian glasshouse, suggesting a humble, utilitarian form in counterpoint to a formal villa typology, with substantial glazing held within a modular timber framework.

What was your approach to the design?

The side extension consists of a carefully crafted brick facade sitting harmoniously within the Petersfield Conservation Area. Its elevation is formed entirely of brick, using various coursing techniques and devices to add richness and variety, commensurate with the crafted quality of the surrounding villa-type dwellings.

New elevations are treated in stack bond coursing, derived in form and arrangement from the vertically hung tiles of the existing house – in both instances the exterior clay finish is non-loadbearing.

To give texture and shadowing to the contemporary facade, the bricks are laid in an alternating pattern of flush and projecting brickwork. This creates a textured surface treatment animated by the play of light and shadow, in keeping with the adjacent cladding in hung terracotta.

What were your ambitions for the extension’s character?

The challenge was to make a relatively large new piece of building that was distinct from the host building, yet also create sufficient connection to the forms and language of the area, so that the extension would fit within this context. The notion of ‘new’ contrasting with ‘old’ was dismissed in favour of a more nuanced approach. As experienced, the extension does not announce itself boldly on the streetscape but sits within it with silent stealth.

Could you tell us about the extension’s detailing?

The ground floor includes a large projecting window that mirrors the principle of the bay window in the host building, which dates to 1903. The existing building’s upper storey is tiled in an arts and crafts manner, using hung terracotta tiles shaped at the lower edge to form a prominent overhang to the coursed brick below. In response, the upper storeys of the new facade extend out to meet the ground-floor window, creating a shadow line across its entire elevation.

Rather than mimic the tiled upper storeys, the new building is treated with stepped patterned brickwork. This gives it a solid, monolithic and sculptural form, yet one that yields and adjusts in response to the host building. An overhanging dry verge detail uses mortar-filled clay tiles and a thick mortar bed between stepped bricks and creasing tiles. This gives a subtly crafted aspect to the uppermost portion of the facade.

To the rear, the extension is formed in home-grown Douglas fir with a black oiled finish and black anodised flashings. It has a bold yet highly crafted character that sits in counterpoint to the terracotta facades of the host building.

How did you realise these details?

The stepped facade and open brickwork patterning were achieved with a cantilevered steel armature, which supports the two upper storeys of brickwork. Further offsetting of the structure at ground floor brings the facade load to the ground while maintaining clear openings for the large window and adjacent perforated brick screen. Privacy screens at ground and first floor are formed in brick held within a stainless-steel frame. These perforated screens allow opening windows to be set behind, while filtering daylight to the interior space, adding texture to the natural light.

Finally, could you tell us about the interiors?

We reclaimed wire-cut bricks from a Hampshire farmstead to use within the interiors. These were laid over an insulated concrete slab with underfloor heating. The bricks were selected for their thermal qualities, retaining heat in the winter months and cooling the space in summer. This also created a richly textured floor plane that unifies the interior spaces while contributing to the acoustic quality. White glazed bricks line the entire interior of the new kitchen, while the elevations of the existing house are exposed internally, giving the interiors the character of an outdoor space.

Robin Lee is the founder of Robin Lee Architecture

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Key data:

Area of extension: 183m²