Digitally Twinned design

Graphisoft's Archicad enabled brp architects to create a virtual building to refine their forward-thinking design for a contemporary home in the middle of Market Harborough

Architectural firm brp architects was tasked with designing a contemporary home in Market Harborough for a retired professional couple.To ensure the property would be future-proofed for the couple's evolving needs, a prerequisite was that it needed to be wheelchair accessible, situated within walking distance from the town centre, and have most of its accommodation on the ground floor. However, the clients were adamant they did not want a bungalow, and although APRA House needed to be built with accessibility in mind, they were keen that it did not look like an 'accessible house'.

Finding the perfect plot
With land at a premium, brp found that the only site that met the couple's requirements in a town centre location was prohibitively expensive. To make it financially viable, the solution was to build two properties on the plot and to then sell on the second house.

APRA House was designed from scratch using Graphisoft's Archicad as Lee Hankins, associate, architect and BIM manager at brp architects explains:

"We have worked with Archicad for many years and over that time we've built an extensive Archicad template. This uses favourites so we're able to model very quickly.

"By creating a virtual building as we model it, any potential issues are highlighted straight away. Furthermore, with the ability to use BIMx and renovation filters to present different options, we were able to demonstrate our plans very effectively to the client, planners and contractors alike."

Visualisations: the key to planning approval
Although APRA House passed through planning fairly easily, the second property proved more challenging as it was visible from the road. Without planning for the second property, the project would not have been viable as the two properties were financially linked. With the help of Graphisoft's BIMx virtual viewing software the architects were able to show the planners exactly how the properties would look and fit in their surroundings.

"The planners loved BIMx; it leaves no stone unturned - really bringing the design to life," says Lee. In addition to BIMx, brp used the Archicad 3D model to create a photorendered visual of the project to overlay on a photograph of the site taken from the nearby park. This illustrated to the local planning authority the minimal impact the building would have and ultimately helped to secure planning approval.

A design for the future
Having previously lived in a 17th century thatched cottage, the couple wanted a very modern property, an antithesis, with flowing open plan spaces that would serve them well into retirement.

The building was created around two diagonally opposed wings responding to the site geometry and maximising the internal space. The main single storey wing contains the reception rooms and master bedroom suite, while the second wing houses the garage and support spaces on the ground floor and the remaining bedrooms on the upper floor.

Lee explains: "For this project we used Archicad's renovation filters to present different options to the client at the early stages of the design process. We do this for all our new builds on a clean site. It makes it so easy to show different options, sizes and material finishes and then delete the ones you don't want."

The largely two-storey space between the wings provides a long tapering hallway and gallery while a bespoke glass and oak staircase maintains the impression of openness.

BIMx to aid client decision making
From an early stage BIMx was invaluable in helping the client to understand how their new home would look. In addition, it helped them to see how their existing belongings would fit, and meant they could make informed decisions when selecting new items of furniture and fixtures.

"We helped the homeowners optimise the layouts of the various spaces by virtually testing different furniture items before they made any final decisions," says Lee.

"In addition, at later stages during construction we overlaid the electrical layout plans onto the 3D BIMx model. This enabled the clients to visualise exactly where the electrical outlets and lights would be positioned which assisted with their final furniture decisions. It also ensured that any changes to the electrical layouts were made before anything was installed on site, preventing abortive works and associated costs."

Materials and technologies
The client stipulated that their home should not be built of brick. Instead, the property was constructed with cavity blockwork together with through-coloured flexible renders in a monochrome mix of whites and greys. The roofs were constructed using powder coated preformed steel trapezoidal panels.

The property's orientation maximises the use of the available sun. The central atrium has high electric windows to draw out warm air during the summer months. Meanwhile, the roof extends over the southerly glazing to offer shading from summer sun, whilst allowing the lower winter sun to enter deeply into the space benefitting from the solar gain.

All of the major building components were specified to exceed the thermal performance of the prevailing building regulations requirements in order to achieve a low carbon, efficient living environment.

Sharing data from Archicad
Within Archicad it is easy to extract the necessary data in a variety of formats to share and work collaboratively with external consultants, engineers and contractors.

Lee explains, "We shared the necessary data with the quantity surveyors and the original cost estimates for the build came back over budget. However, we were able to quickly identify where the bigger expenses were and by working together, we reduced the overall length of the building slightly. This significantly reduced the overall cost."

"We also shared data with the kitchen manufacturer in dwg format, as well as schedules, drawings and the BIMx model with the builder. Sharing the BIMx model with the builder was particularly useful in helping them to understand the design."

Brp worked closely with the builder throughout the project, with monthly formal meetings and regular site visits to monitor progress.

The construction was completed both on time and within budget, with the project summed up perfectly by the forward-thinking homeowners: "It has been a fantastic experience to see a derelict plot of land morph into a singular and innovative piece of architecture, which is not only beautiful to look at but practical to live in and environmentally sound. This is form and function perfectly combined."