Terrace extension creates a home office with a 'birdhide' feel

Can you decribe the project Ambacht took on?

The house is set in a 1930s development along the Dodder River in south Dublin. An old box extension was removed and a room created to provide dining, living and a home office space. The room wraps around a courtyard, while clerestory fenestration captures the sky and sun allowing both to penetrate deeply into the space.

A desk sits low under a mono-pitched roof, sunk below the level of the garden like a birdhide and hidden from view. The planted courtyard defines and separates each functional area providing them with air, light and sheltered views onto the occasional visiting birds.

Who is the project for and what was the brief? 

The project is for a young couple looking for a transformation of their house to create spatial interest, a stimulating environment and a workspace ‘that felt in the garden (bird hide feel)'.

Were there any significant factors that influenced the design?

As with most terraced houses, the narrow 5.5m plot proved challenging to extend while not adversely affecting daylight in the rooms of the existing house. Also, the terrain gently stepped down towards the garden, something we made use of by nestling the new room into its surroundings. Keeping budgetary constraints in mind, the footprint of the new room was kept as small as possible.  

Can you explain the external treatment of the project? 

The garden room sits on a continuous red brick plinth which references the brick detailing of the front facade and seamlessly meets the window’s matching reclaimed brick sill. In the new courtyard, brick is perforated to form a garden wall where air and light from the adjacent lane can filter through.

The gutterless metal corrugated roof performs a double function. The ‘silver’ finish acts as a big reflector, increasing the natural daylight levels deep into the existing house. On rainy days the corrugation enables the rain to fall freely in little streams down into the courtyard, providing visual interest and a greater connection with the natural elements.

Can you explain how the interiors have been designed? 

Red oxide steel beams, columns and timber beams are pulled away from the thermal envelope to provide space for light and shadows, which change continually through the days and seasons. Timber panelling, at a height set by the floor level of the old house, wraps around the new extension. This gradually steps down to form, in part, skirting boards, benches, wainscotting, shelving and ultimately the desk. Terracotta red light pendants, tiling and the sand/cement wall finish all nod to and complement the exterior treatment of the existing house.

What has been the project’s approach to sustainability?

The house has been upgraded to current thermal and ventilation standards, with underfloor heating. The spatial moves of the new room – the courtyard and shape of the roofs – enable daylight to enter the house abundantly into what used to be an artificially lit dark space. Additionally, brick cappings and brick sills – no longer in production – have been reclaimed from a salvage yard and existing foundations have been partly reused. Internally, the structural steel and timber beams are left in their raw, undecorated state highlighting a sensibility to materiality, nature and the environment.

What was the biggest challenge, and how did you overcome it? 

Programmatically, combining a full-time home office with a domestic living space in a narrow plot poses frictions in terms of privacy, noise and visual distractions. We resolved this by sinking the work station as low as possible with the desk levelled with the garden – like a birdhide. By staggering the dining and desk spaces, in combination with the tall clerestory windows, fitted furniture and the introduction of the courtyard, the dining and living areas can look out and over the desk without looking into it.

What is your favourite detail in the project? 

Instead of combining and concealing the roof structure, all individual elements are stacked on top of each other and left exposed: the birch plywood roofing deck sits on the timber roof joists, which sit on the steel beams. The positioning of the windows allows sunlight to filter through the joists, creating a play of light and shadow constantly in flux. It also enables residents to look through and see the sky and surrounding trees.

Are there lessons from this project which might be applied elsewhere?

Working from home has become increasingly prevalent. This project was an interesting exercise of a new model of living and working in a compact, yet spatially stimulating environment.

Bram D’hoedt is director and co-founder of Ambacht

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