House & GardenadviceRenovationsProperty Advice

If space is at an all-time premium in your home and you’re thinking of expanding up, out or down, there are some hard questions you need to ask first, writes Harvey Grennan.

Drive down any street in any Australian city or town and you’ll see a ‘renovator’s dream’ being transformed, a new home taking shape or a second-storey conversion underway. Renovating is a national pastime and when we’re not doing it, we spend a lot of time thinking about it. The results of a well-considered renovation can be positively life-changing but, like all big decisions, there are some pros and cons you have to consider before taking the plunge.

“If you spend $1 on a renovation and get back $1.50, it’s worth it. If you get back 90 cents, what’s the point?” says builder Domenico Alvaro of Alvaro Bros, who executes high-end renovations and home additions across Sydney.

Architect Jim Allman of Allman Johnston Architects, based in the NSW Southern Highlands, makes the same point: “You have to be careful not to overcapitalise unless the house has a personal value beyond dollars or you intend living there for a least 10 years,” he says. “Retain as much of the existing structure as possible. If you change the structure, there are risks and you’ll pay a premium to get a builder to do that sort of work.”

The first question to ask is whether the renovation is worth doing at all. Will you spend more than you would if you demolished the house and built from scratch? How much rectification of the existing house is required? Architects use a rule of thumb: if a renovation will cost more than one-third of the cost of building a new house, it’s probably uneconomical.

The next question is what the renovation or addition will cost, and how much you can afford to spend. Paying a bit more for better-quality finishes may pay you back many times over when you ultimately sell, Alvaro advises.

Balance and perspective

What sort of renovation is best for you? Should you just paint and carpet, replace the kitchen and bathroom, or open the place up? If you need more space, should you go up, out or even down?

Sometimes people do too much, says Allman. “You can make a place look like a million dollars simply by renewing finishes – new cladding, a new roof, skylights, a paint job and refurbishing the floor. Kitchens and bathrooms are a good place to start. Often it’s the little details that make the difference. It’s easy to add elements that give a lot of value for not a lot of money, perhaps a gable-fronted portico or nicely detailed steps at the entry, or a pergola covered with a vine at the back.”

Older houses may need opening up to light. “The priorities in renovating older-style homes are to get rid of long hallways, make rooms and windows bigger, make the house more open and free-flowing, create indoor-outdoor living spaces and improve thermal comfort,” says Allman. “It’s a good idea to introduce flexibility. Allow walls to open and close as your mood and the climate dictate. A courtyard can become part of the interior space.”

Alvaro warns of wasteful renovations. “It doesn’t pay to add just one room upstairs because you will lose a room downstairs with the stairway. If you can get, say, two bedrooms, a sitting room and a bathroom in an upstairs addition, then it’s worth it.”

Up or out?

It’s almost always more economical to extend on the same level. According to Alvaro, it typically costs about $2800 per square metre to extend outwards and $3200-$3700 to go up. (The larger the extension, the cheaper the rate per square metre, as the cost of the stairs is amortised.) Allman suggests it will cost 50 per cent more to extend upwards rather than outwards. Of course, costs will vary with the design and the particulars of the site.

Going up costs more because the roof has to be removed and the lower storey temporarily protected against the weather. You’ll pay three times, says Allman: for the new work, to marry it to the existing house, and to patch everything up.

With a single-storey addition everything you do is a gain, says Alvaro. Going up, however, can be a double-edged sword, according to Allman: “There is the opportunity for greater architectural expression and a better outlook. It’s more compact and leaves the garden intact. It has an insulating effect on the ground floor and you avoid site costs such as slabs and footings.

“On the other hand, you are paying more for the height, it’s more difficult for the builder with ladders and scaffolds, you must weatherproof the lower floor and there may be issues of overlooking or overshadowing neighbours.”

The down load

Digging down is the most expensive option and usually viable only if the site is on a sloping block or space is at a premium. It may involve underpinning the foundations of the existing house. Expect the cost to be double that of a single-storey addition.

Options for digging down include a garage, family room, wine cellar, office and music room. “It’s not as fraught or as expensive if the new space is not a habitable room, such as a garage, as the finishes and waterproofing are not so critical,” says Allman.

Consider how close the excavated space will be to the boundary, what services would need to be relocated and whether you’d be digging into clay, sand or rock. Rock may be more expensive to excavate than sand, but it supports itself and doesn’t require retaining walls.

What not to do

Don’t be too radical or you may end up with a dog’s breakfast. Update and modernise by all means, but stick to a unified theme, whether contemporary or traditional. Don’t destroy the intrinsic value of what you already have.