Feature article

How building another storey can add priceless value

If you like the home but need more space, adding a second storey, popping the top, could be an option.

14 March 2023

What you’ll learn:

  • Find out if ‘popping the top’ is structurally possible for your home
  • Find out if the planners would give the go-ahead
  • The pros and cons of adding another storey to your property

There’s all kinds of questions to consider when thinking about adding another storey to your home. Among the first things to think about is where you’re going to put the stairs and whether you’re prepared to lose the space they’ll take up. It can be a lot of money for not acquiring that much extra space. But oh the views and the separate living!

Good questions to ask:

Is an extra storey possible structurally at your home, or the house you have in mind?

Ray White Mt Eden agent, Rick Mozessohn recommends consulting a structural engineer or architect to see if another storey is feasible at the property. They will also check the height to boundary restrictions and make sure you’re not going to be building out anyone else’s views.

What do you want to use the space for?

It’s possible you want to use the space to have some away time from the kids, or it could be that the extra storey will be for the teens to have their own bedrooms and privacy. Just make sure everyone’s clear what these extra rooms are for and how everyone benefits from the extension.

How many rooms are you going to add?

Architectural designer Richard Furze who did his own “pop-the-top” project in Sandringham says, if you’re going to put one room up there, you may as well put two or three. He has completed a project where he designed three childrens’ bedrooms and a shared lounge upstairs for a family. His tip – make sure you put in good insulation and high density floor materials to soften any over-exuberant thumps happening upstairs.

Does my home style lend itself well to a second storey?

Richard says that bungalows and state houses are especially well set up for a “pop-the-top” project. It’s relatively easy to add a story to homes built between the 40s and the 70s,, because of the way they were constructed, he says. Villas are trickier because of heritage restrictions, you’re typically not allowed to change the street view or character of the home, says the architectural designer.

What style should the second storey be?

Whatever style the main house is, the new storey should be in keeping with the rest of the home, says Christchurch Bayleys agent, Sarah Eastmond. Then, you’ll have no trouble reselling when the time comes to downsize. Nobody likes a quirky extra storey addition that looks out of place with the existing home.

What room am I going to sacrifice for building the stairs from the ground floor to the top floor?

This probably won’t be the first thing you think about when you envisage an extra storey on your home, but it’ll be one of the first questions the builder or architect asks. Best case scenario is it’ll be a generous linen cupboard or a small bathroom that you have to take away, but if not it might be part of a bedroom or a living room. Richard says you might be able to sneak a bathroom or laundry in under the stairs so the space won’t be lost completely, but you should be thinking of some of these ideas early on.

Bonus idea: If you add another storey to your home, think about building attic trusses in the roof space which leaves the door open for extra attic storage or an extra room, advises the designer.

Furze Architecture + Design

*Photos by Simon Devitt

What’s the price of adding an extra storey?

The answer to this question depends on the quality and finish of the existing home. As a rule of thumb, an extra storey will cost more than a rear extension because you won’t “win” as much space with another storey as you do with just expanding out the back. You’ll likely gain another 60 sq m rather than the 100 sq m you might get with an extension on the main floor, says Richard, so there’s not as much bang for your buck.

Nine Yards consultant and renovation specialist, Jen Jones says depending on complexity and finishes, (and if the extension includes a bathroom) the cost would be around $4000 to $6000 per sq m, so that means the budget would be around $360,000 for another storey and some more if you’re re-doing a room downstairs that’s been reduced to accommodate the staircase.

A ground floor extension is easier, she says. But if it gives you separate space from the kids and a beautiful view, that kind of extra room is priceless.


Gill South
Gill South