How To Build A Roof Extension

Roofs are essential parts of houses because of their protection against rain, sunlight, snow, and wind. They keep homeowners safe during natural disasters. Aside from maintenance and repairs, one thing you can do to improve your roof is a roof extension. This article will tell you all you need to know about roof extensions, their benefits, and some unique roof designs you can explore to make the most out of a roof extension. 

What are roof extensions?

This is the process of adding a new rafter to your existing one. What’s great about this home renovation project is you are creating new space without spending too much money. This is because you can extend a roof without the need to alter the structure of your home, so you don’t need to build a new wall or install support posts. 

Types of roof extensions

Although most prefer their roof extensions to match their existing roof, no rule says your extension should be of the same style as your main roof. However, some roof types look better if their extension is of the same style. You can consult a roofing contractor, a building expert, or an architect to choose an extension that will match your needs and budget. Here are some popular designs you can consider:


Skillion is a single sharp roof incline you often see in porches or sheds. It is a budget-friendly option and easy to construct. This is an ideal option if you want to add a skylight or if you need additional storage in your attic. It is also ideal if you live in an area that experiences a lot of rain because it excels in allowing water to run off. 

Gable Roof

A gable is a triangular roof style you often see in classical house designs. This is an excellent choice if you want to create an internal space or if you want to add an attic. 

Flat roof

This is the simplest among extensions and is ideal for extending over any space without additional posts or pillars. 

Glazed roof

Instead of traditional roof materials, this type of extension uses a sheet of glazed glass. This is an excellent choice if you want to create a sunroom or if you want your extension flooded with natural light. 

A roof extension over a doorway creates a sheltered outdoor living area. The new roof could also block excessive sunlight from entering a room. You should possess basic carpentry skills before attempting to learn how to build a pitched roof extension. You may also need to obtain a building permit depending on where you live.

  1. Determine the height and angle of the pitched roof.
  2. Mark the horizontal locations on the existing wall for the top and bottom wall plates. The wall plates will connect to rafters and joists.
    1. Use a level and chalk line to create the lines.
  3. Cut lumber for the wall plates.
  4. With a power drill and wrenches, attach the wall plates with anchor bolts.
  5. Cut rafters with angled notches on the upper ends to fit against upper wall plate.
    1. The combination square will be needed to mark angles for cutting.
  6. Cut bottom ends of rafters at an angle parallel with the existing wall.
    1. Test the fit of your first board and use it as a template to cut other boards if it fits.
  7. Cut joists to fit to bottom wall plate and connect with rafters.
  8. Nail rafters to top wall plate.
  9. Nail joists to bottom wall plate and connect to rafters at roof edge.
  10. Cut and fit plywood for roof decking to nail over rafters.
  11. Spread roofing paper over new roof and nail in place.
  12. Shingle the new roof, starting at the bottom and working your way up.
  13. Attach soffit boards underneath roof overhang.
  14. Nail on fascia boards.

Tools & Materials

Select saw blades and drill bits appropriate for the types of materials that you’ll be working with. For example, you’ll need masonry bits if you’re anchoring wall plates to a brick wall.

  • Power drill
  • Circular saw
  • Wrenches
  • Hammer
  • Combination square
  • Ladder
  • Level
  • Chalk line

Final words

Roof extensions are cost-effective means of adding space to your homes, making them excellent home improvement projects. With the help of roof extensions, you can build an en suite bathroom, a garden room or an outdoor kitchen without resorting to drastic home renovations. talk to one of our project consultants and get free quotes for your project. Start planning your roof extension project in no time.

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