How much does it cost to add a dormer window?

A dormer window can add style and character to your home, as well as increasing the headroom and maximising the usable floor area, and can transform a cramped attic into a full-height room with plenty of light.

Rooftop dormer window of UK home

Loft conversions have long been popular, but these days you don’t have to be content with awkward sloping ceilings and small roof windows or skylights. Choosing a dormer window instead adds style and character to your home, as well as increasing the headroom and maximising the useable floor area, and can transform a cramped attic into a full-height ‘room-in- the-roof’ with plentiful natural daylight.

What is a dormer window?

A dormer is a vertical window, with a roof of its own, which sticks up from the slope of a pitched roof. It’s a great improvement over a skylight because it offers views to the outdoors just like a ‘normal’ window and creates a greater sense of space. Similar to skylights, dormer windows are a source of light and ventilation roof or loft spaces, but unlike skylights, they also provide the opportunity to increase the amount of headroom in the room and allow for more usable space. There are many different dormer styles, generally named according to their roof type. Choose one that is aesthetically pleasing and complements the architectural style of your house.

Flat roof dormer – The simple flat roof dormer is one of the cheapest to build and often creates the most additional internal space.

Shed dormer - Similar to a flat roof dormer, a shed dormer features a single-planed roof that slopes downwards at an angle shallower than the main roof.

Gable dormer – Also called a gable-fronted or dog-house dormer, the gable dormer has a simple pitched roof. Usually considered a more traditional and attractive option than the flat roof dormer, it’s a popular choice for period homes.

Hipped dormer – A hipped or hip roof dormer has three sloping planes, the same as a full-size hipped roof, where they are normally installed as a matching feature.

Eyebrow dormer – An eyebrow or eyelid dormer is unique in having no sides; instead, the roof covering curves up and over a low, wide window. Originally found on thatched cottage roofs in the Middle Ages, this traditional style is beautiful on the right property.

Other less common dormer windows include the bonneted dormer (arched roof);

Nantucket dormer (large three-in-one dormer with two gable dormers and a connecting shed dormer);

and the blind or false dormer (provides no space or light internally, but can be a useful design feature externally).
Dormer windows can enhance the look of any home and, especially when thoughtfully designed and constructed, can add significantly to the value of your property.

Will I need building consent to add a dormer window?

Building consent is usually required for structural adjustments such as additions and alterations. For more information, check with your local renovation specialist.

What can you achieve with a basic budget?

There are plenty of ways to add a dormer to open up your loft and create extra floor space on a budget. A dormer is usually added at the same time as a loft conversion, so the cost is an ‘add-on’ rather than a standalone price. A smaller dormer is normally cheaper than a larger one, and using simple materials will keep the cost down. Adding a dormer window to an existing space in New Zealand is likely to start from $15,000.

Cost of adding a dormer window on a basic budget

From $15,000.

What can you achieve with a mid-range budget?

With a little more to spend, you can add dormer windows designed to enhance the overall design of your property. Period-style dormers for cottages, barns, Victorian, Georgian or modern house types can make your home unique. More expensive materials may be needed to match the existing construction, particularly if you live in a heritage-listed home.

Cost of adding a dormer window on a mid-range budget

From $30,000.

What can you achieve with a high-end budget?

When money is no object, bespoke dormer windows can add an impressive feature to your home as part of a loft conversion or elsewhere. Depending on the style and period of your property, a large Nantucket dormer or an eyebrow dormer could be added above a full-height hallway. This will increase the light and sense of spaciousness, and create a stunning first impression when welcoming guests to your home.

Cost of adding a dormer window on a high-end budget

From $60,000.
For further inspiration, check out these loft renovations.

Get in touch with Refresh to discuss your home renovation project

If you would like to discuss options and ideas for your kitchen renovation project, please use the enquiry form on this page to provide us with your contact details. We will get in touch with you at a time that suits you to discuss your project. If you would like to provide us with more information about your project, we have a more comprehensive enquiry form on our "Get in touch" page too.

*Costs are rough estimates and are subject to change. For a fixed-quote accurate to your specific project, please consult your local Refresh Renovations specialist. All Refresh Renovations franchises are independently owned and operated.

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