Penthouse Roof Terrace in Liverpool

We originally met the client of the including a seaside themed area on the part of the wrap-around roof that faces out towards the Mersey estuary.

Penthouse Roof Terrace at Tatton RHS Show in 2017, their original brief was to create a roof terrace with garden studio and different areas to enjoy,

The brief evolved as the design process continued with lots of input from the client, inspired by trips to Japan and also a late addition to bring in their love of Mondrian – an eclectic brief which was at times challenging to work with and a risk to bring together, but resulting in a successful project and an overwhelmingly happy client.

Having not taken on a roof project before we were keen for the challenge and were leaning on the knowledge of our colleague who had worked with roof projects previously.

Building up a relationship with the client

Whilst the design layout of the roof terrace was in process, we worked with an Interior Designer, (EmmieB Interiors), Architects (D2 Architects, Chester) and Structural Engineers, to apply for planning and once the design layout was agreed and planning was in place, we started working out the logistics of the installation.

By this point we had been working with the client for about 18 months, so had built up a great relationship and trust. We agreed between us that the logistics of the project were difficult to put a value on and to save a long involved costing of the project with many approximates and unknowns, that we would work on a day rate basis for installation and a cost plus 10% for all materials. The client was happy and more than comfortable with this.

Challenges that were faced

The main challenge was that the roof was 7 stories high, just outside the centre of Liverpool, so road closures had to be in place every time we required a crane lift.

We agreed with the local council regarding parking permits on the road outside as there was nowhere else for our vans to park in close proximity.

Another challenge was the roof membrane which we had to have professionally checked for punctures several times before and during the project to ensure no damage had taken place during works. Part of the project was to design, manufacture and install new balustrade around the perimeter of the whole roof. We worked with the client and the structural engineer on the design, and the client instructed a local contractor to install the frame (without the glass). We then instructed a netting company (G&M Safety Netting, Middlewich) to install a safety netting to the framing prior to us starting works on site.

The main logistical challenge during works was the weight loading on the roof. The calculation was to have no more than half a tonne per sqm, so this meant any pallets or bulk bags of materials had to be reduced to be no more than this amount, so it was a logistical challenge to work out how much space we had each crane lift. We had to plan each lift to precision, creating a map of the roof and where we would place each item to ensure we could still work around it to construct the works.

The installation process

The installation of the bulk of the project took approximately 10 weeks. Once the Garden Studio (by Swift Garden Rooms) was in place, (crane lifted on), all the London Stone porcelain paving was laid first on a pedestal system, then the deck frames were installed, again on a pedestal system with composite framing, and Designboard decking.

Built in seats with hinged lids for storage were then constructed, again using the Designboard, then various pebble areas, the seaside themed side area (incorporating a reclaimed timber boat sourced locally), old snooker table slate repurposed into an outdoor kitchen unit with a Kamado Joe ceramic grill and bridge, planters, soil and planting.

Exterior lighting and irrigation supplied by Landscape Plus was also incorporated throughout. The project also features a copper tree water feature, a growing area, polished concrete gas firepit by Davinici Designer Concrete and reinforced concrete pads installed under the deck for the client to retrofit a Renson Louvered Roof Canopy in the future, subject to planning.

The end result

Although a particular challenge, resulting in plenty of sleepless nights, we really enjoyed working on the project and collaborated well as a team, including the client. It was a great working relationship which helped the project come together so well and with ease.

The client was over the moon and even had tankards engraved for the site staff with the project name, also presenting both Holly (designer) and Glynne (Project Manager) with cut glass ornaments engraved with ‘Mother’ and ‘Father’ of the project, a lasting memento of a project to remember!