The new bulbs are LED. They use less electricity. That does not automatically mean the old recessed housings above them can be buried in insulation.
The fixture assembly has instructions of its own. Read those before the attic top-up makes its label hard to find.
Identify the whole fixture
Have the installer or electrician identify the housing, any driver or junction-box arrangement, and the applicable listing. Insulation-contact suitability describes whether insulation may contact the listed assembly under its specified conditions.
Airtightness is another question. A fixture can be suitable for insulation contact without resolving every air-leakage path around its installation. The ceiling air barrier still needs an appropriate detail.
Do not improvise a cover
NRCan's materials guide discusses recessed-light covers and precautions around heat-producing components. Select a compatible approach from the fixture instructions and qualified advice; a household container is not a tested electrical accessory.
If the existing fixture cannot be identified or is unsuitable for the proposed insulation work, ask a licensed electrical contractor to assess replacement or another compliant detail. A new lamp inside an old housing does not relabel that housing.
Put this before the insulation delivery
- Record the fixture models and relevant markings.
- Identify any required clearances and compatible covers.
- Resolve wiring or equipment concerns with the electrical contractor.
- Complete the appropriate air-sealing detail.
- Photograph the arrangement before it becomes concealed.
The order matters. Digging through a fresh blanket of insulation to solve a known fixture issue is avoidable work.
Check more than the lights
NRCan's attic guide also calls attention to chimneys and other heat sources. Have the insulation scope account for the actual attic, rather than assuming the open areas around each object were accidental gaps left by the previous installer.
An attic top-up can still be a straightforward project. The useful catch is that its preparation may include an electrician and a few small details nobody will see from the room below. Those details belong in the quote before the bags arrive.