For Andrew and Christie Dawes, of Merewether, their undertaking had to tick a lot of boxes and conquer a few more obstacles than most. However, the outcome shows what can be achieved with savvy design, perseverance and a unified vision.

Their wish list was specific: create a guesthouse at the back of two properties; it must be separate to the other dwellings; it needed to be wheelchair friendly and thus on the same level as their current home; it must be fully self-contained; and it must be suitable as accommodation for visiting family and friends, or private enough for hiring out as a short-term rental property. No small feat.

The couple approached Lachlan Craggs of Craggspace Architecture to help them navigate their requirements, while keeping the look and feel in line with the existing properties.

He set about designing a "studio style accommodation space with open-plan bedroom, living, kitchen and dining area with an ensuite bathroom located at one end of the building".

The project also included a plunge pool, a laundry and storage structure and new decking linking the studio to the existing residence with easy transitions.

"We wanted to create a space that was every kind of friendly," Christie says.

"I have been a full-time wheelchair user for almost 30 years. Outside of my home I accept that access is not always going to be ideal. However, on my own property, and in my own home, I was adamant that access take precedence."

First they had to conquer Obstacle #1: the floor level of their home was lower than what the new floor needed to be, as the property is in a designated flood zone.

"Matching the floor level of the existing residence would usually be an easy process, however the site is in a flood area, and the planning floor level was technically higher than the level of the existing house," Lachlan says.

"Obviously this was an issue for wheelchair accessibility, but thankfully we were able to negotiate with council, and they allowed us to drop the floor level to match the existing residence."

Then came Obstacle #2: the new guesthouse development was to be built across the boundaries of two properties, but a bit of clever positioning and savvy design meant this too, was easily overcome.

"Local council heritage restrictions meant that we could not make any subdivisions or boundary adjustments," Christie says.

"The design had to allow for the properties to be easily separated in the future ... so the only structure running across the boundary line is the deck, which can be easily modified to re-establish the original property boundaries."

Bull Building was engaged to undertake the work and clever, quality inclusions were installed to become beautiful and functional parts of the space.

Polished concrete flooring was placed throughout the internal areas, including the ensuite, to create smooth transitions and a uniformity through the space.

"This was done with a double slab system - pouring a topping slab over a waterproofed structural slab that was set down in the wet area," Lachlan says.

The hard, flat surface makes accessibility easier, meets waterproofing standards and it has underfloor heating to boot.

"We also made sure doorway transitions were smooth, and doorway widths were wide enough to allow easy wheelchair access. The planning of the studio was also highly considered to allow access around all areas, furniture and spaces."

Subtly and nifty placement has allowed for features to be supportive without breaking with the aesthetic. Wall hung vanities which allow for larger turning circles, roomy wet areas without hobs, flip mixers instead of taps and freestanding tubs are beautiful and on trend, yet practical.

Clever storage also features: pull-down wardrobe hangers, pull-out pantry drawers, kitchen kick-board drawers to fill dead space, and bespoke cabinetry. Double-glazed windows reduce glare and noise and sleek James Hardie Matrix and Axon cladding connects the guesthouse visually with the main residence.

The studio is warm and relaxing with modern coastal-themed finishes, yet bright and sleek in its aesthetic. Most importantly, the owners are happy at the end of the collaboration, with the initial issues worked around and smart solutions implemented. Add in two small children, pets and wayward weather during the build, it's a wonder Andrew and Christie are still smiling, but they are.

"I am proud of the entire project," Christie says. "Having the guesthouse means we can connect with our family and friends more often, and for longer periods. It also provides us with an extra income stream, which is very handy."

"The finished product far exceeds my expectations," she says. "The small, but well-designed guesthouse is able to perform every function expected from a regular home...the whole development flows beautifully."