Where a new skylight can go
A new skylight can go where the framing, the roof pitch and the room below allow it. The rafters set the width. The pitch sets the type of unit. The room sets how much light you want and how much heat you can live with.
Start inside the house. Look for a hallway that never gets light, a bathroom with no window, a stairwell, or a kitchen with a dark corner. Then check the roof above that spot. A skylight cannot sit over a valley, a chimney or a wall-to-roof joint without extra flashing, and we flag those at the estimate.
New skylight installation: types and options
New skylight installation starts with the unit, and there are three decisions.
- Fixed or venting. Fixed units are simplest. Venting units open by crank or electric and fit baths and kitchens.
- Deck-mounted or curb-mounted. Deck-mounted units flash straight to the roof deck on a pitched roof. Curb-mounted units sit on a raised frame, needed on flat roofs.
- Glazing. Laminated or tempered glass, low-emissivity coatings and tint all change heat and light.
A tubular unit is a fourth route for small spaces: a small dome collects light and a reflective tube carries it down. It needs little framing and suits closets and hallways. For a bigger opening, a framed unit is the answer.
What a new skylight installation includes
- Location check from inside and on the roof, with rafter spacing
- A cut and framed roof opening, headered where rafters are cut
- The unit on a deck mount or curb
- Flashing laced into the roof covering and tested
- Light well framing or coordination with your drywall trade
- Cleanup, photos and a walkthrough
Flat roof skylight and skylight on low slope roof
A flat roof skylight sits on a curb, and the curb is the whole detail. It is a wood or metal frame, raised above the roof, that is flashed into the membrane on all four sides. Water has to run around the curb, so the roof around it needs to drain properly.
A skylight on a low slope roof follows the same rule. Manufacturers set a minimum pitch for deck-mounted units, so a nearly flat roof gets a curb. On a flat roof, the curb is built before the membrane goes down, which makes skylight installation easiest with a new roof. On an existing membrane, we cut the opening and tie the new flashing into the old roof with extra care. Where the roof is also due for work, our team may recommend doing both together.
Skylight permit in Alameda
A skylight permit in Alameda is a question to settle before you order the unit. The City of Alameda Permit Center says permits are needed for most construction work, and the process is online. Cutting roof framing is structural work, and work that changes the exterior of a historic home may also need Planning design review, so ask before you change the look of an older house.
Because no skylight-specific rule is published that we could verify, we do not guess at one. The estimate states who pulls the permit, and you should confirm with the Permit Center. If you have a homeowners association, read its rules on roof penetrations as well.
Added skylights also face energy-code limits on heat loss and solar gain, shown on the unit's NFRC label, and secondary guides describe size allowances that differ by code cycle, so ask the Permit Center what applies (BayREN 2025 guide). Cutting into a roof is roofing work under the C-39 classification, so check any installer's license and bond at cslb.ca.gov.
The installation steps
- Decide the location with you, from inside and on the roof.
- Check rafter spacing, attic access and the light well path.
- Write the estimate with the unit, framing, flashing and light well listed.
- Confirm the permit path and any association approval.
- Protect the room, then cut the roof opening and frame it.
- Set the unit, flash it into the roof covering and test the joint.
- Build or finish the light well, or coordinate it with your drywall trade.
- Clean up, walk through the result and send photos.
What does a new skylight cost?
A new skylight costs more than a swap, because the opening, framing, flashing and light well are new. The unit type, roof covering, pitch, attic access and light well finish drive the price. No verified local price exists in our sources, so we publish none.
Curb-mounted units on flat roofs add the curb and its flashing. Venting units add the operator, and electric ones add wiring. Compare installers on the written estimate alone, so ask for a list that separates the unit, framing, flashing and interior work.
Is a bathroom skylight a good idea?
A bathroom skylight works when the unit vents or the room has a good fan. Moisture is the issue, because warm steam meets cold glass and condenses. Choose a venting model or a fixed one with good glazing, and run the exhaust fan longer than you think you need. Our skylight repair page explains how to tell condensation from a real leak, and the skylight replacement page covers older units.
Where we install skylights
We serve Alameda and the East Bay from the West End. Oakland is about 12 minutes from Webster St, Berkeley roughly 18, San Leandro about 24, and Castro Valley around 35, with the bridges and tunnels as the variable.