By Ann Robinson and Annie Schwemmer

Everyone has seen a bad remodel.

You’ve seen the house where the new addition looks like a big shed bumped up against the house, or the second story that looks as if it could have fallen from space and just happened to land on a particular house.

Remodels don’t always have to exactly match the original house, but they do need to relate to it. More than anything, the key to achieving a seamless blend of the old and the new has to do with the roof. The shape (or massing) of the roof is critical and may require the trained eye of an architect to help you with this design issue, but the material used on the roof is also key to the success of the project.

One of our clients hired us to remodel an old addition to help it blend in with the rest of the house. They knew they would have to redo the roof for two reasons: First, the old addition’s roof was flat, and second, it was leaking.

These clients understood that a roof has a lot to do with defining a house’s personality. They felt that the 1920s prairie style of their home called for the look of a classic tiled roof. However, the existing roof structure couldn’t handle the weight of the tiles. Concrete and clay tiles tip the scales at 500 to 800 pounds per square (or 100 square feet or a 10-foot by 10-foot area of the roof) for the lightweight versions, and 900 to 1,200 pounds per square for regular tiles.

Right Roofing material

Using concrete tiles on the roof can help seamlessly tie a home add-on into the rest of house.

Strengthening the roof structure added a few more months to their construction schedule and more than a few dollars to their budget, but the upgrade to the roof and the home’s curb appeal made it worth it to them.

While some projects can get away with matching the roof of the addition to the existing roofing material, it is often a good time to replace the entire roof to help minimize calling attention to the new addition. It is important to understand the materials you are choosing and what your existing roof can handle.

When deciding on a roofing material, cost is often a factor.

Asphalt shingle roofs usually cost from $50-$150 per square. Though building codes generally allow up to three layers of shingles, tearing off the existing shingles is highly recommended. This will add another $30-$50 per square to the cost.

Metal roofing and concrete tiles may start at $100 per square and run up to $600 or more for coated steels and copper. Ceramic tile and slate are also considerably more than asphalt shingles. Clay tiles can cost $300-$500 per square. Slate, with its need for skilled and experienced craftsmen, can cost up to $1,000 a square.

Initial cost is just one consideration, though. You’ll be lucky to get 20 years from a cheap asphalt shingle, but a good slate roof could easily last a hundred years or more. Some cement and metal roofing products come with 50-year warranties, so spending more up front can buy more years of service from your roof.

For commercial projects, architects sometimes use a “life-cycle cost” comparison that factors in maintenance and replacement costs to justify spending today’s dollars on a material with lasting value. By that calculation, cement tile or even slate could be a good buy in the long run.

Fire safety, pitch and snow buildup, and energy efficiency are among other considerations when selecting a roofing material. Take a good look at code requirements in your area, how much hot sun your roof is likely to encounter, and the precipitation it will need to shed. These questions will help pinpoint your ideal material.

Remember, when adding on to your home, one of the key things you can do to ensure your addition blends well is to choose the right roofing material. Even after all the added expense and time (including surviving a few more rain storms with their roof torn apart!), our clients are happy with their new tile roof. Not only do they have the curb appeal they desired, their addition finally looks completely at home. As always, we welcome your home architect design questions at

Right roofing material is key to blending home addition