Sure. Thank you very much for the question, Mr. Chair.
I will speak first about the lobbies. We looked at two options essentially for the chambers. The option that is proposed here—and these costs include the work on the galleries in the chamber and for the lobbies—is costed at approximately $75 million. The alternative option, which was the expanded chamber option that we looked at, was a little in excess of $300 million. Those were the two comparative options that we looked at. The proposed option here, which again includes the work on the galleries, the chamber and the lobbies, would be approximately $75 million.
On the light-wells, as you quite correctly point out, there are a number of puts and takes from a cost perspective, so it is a little more complex. We could come back with cost comparisons on that, because there are the energy consumption considerations. The covering in the light-wells is essential to the sustainability strategy for the Centre Block. We have a carbon-neutral strategy for the Centre Block. Before it closed, the Centre Block was the worst performing from the perspective of energy performance, energy usage and GHG emissions within our portfolio. That is essential to the strategy, going forward.
The other thing that would be important to note is that, especially with respect to the west and east courtyards, the use of these courtyards provides universal accessible access for Canadians to the galleries. Without using the courtyards in this way, we would have to find another and probably more costly way that would impact the heritage components of the Centre Block.
This sidesteps a number of those issues. It is critical to the sustainability strategy, it is critical to the universal accessibility strategy and, as the Deputy Speaker indicated regarding the growth in the number of parliamentarians, it provides some additional elbow room for the building, which is critical. It's part of returning the Centre Block to the original vision of John Pearson, of making sure that there's symmetry, a light-filled space and common-use space for Parliament. This is essential and has been a bit lost over the years as functionality has, with the need for space, overtaken some of this common space.