In the original sketch of the Sun Room: #14 (comment) I used quite a lot of glass ...
Sadly the price has sky-rocketed since the 2020 pandemic so it's no longer feasible to have as much of it in the build.
But I still want around 8-10 m² of it to allow light through to the lower levels.

http://simulador.giuditta.pt/publicFTP/Tabela_Precos.pdf

Also came across this calculator used by civil/costing engineers:
http://www.geradordeprecos.info/obra_nova/Fachadas/Vidros/Especiais__seguranca/Vidro_laminado_de_seguranca_0_0_0_1_0_0_0_0_5.html

This is the lower-bound of the cost/price we can have in-mind when finding our eventual supplier.
I'm operating under the assumption of spending 170/m² for the glass.
Though depending on the complexity/quantity needed, it could be marginally cheaper than this.

If it comes to it and the PT-based suppliers want toooo much money, I'm not averse to ordering it from China:
https://www.alibaba.com/trade/search?tab=all&searchText=structural+glass+panels+10mm

e.g: https://www.alibaba.com/product-detail/tempered-laminated-structural-glass-floor-panel_1600795268593.html

Seller: https://vattiglass2.en.alibaba.com/minisiteentrance.html?spm=a2700.details.0.0.76a2733bW9PtSE&from=detail&productId=1600795268593

https://www.alibaba.com/product-detail/Factory-custom-anti-slip-transparent-interlayer_1600690012663.html?spm=a2700.details.0.0.1c2023a0k1Lyvi

@iteles what are your thoughts on ordering a sample from China ASAP so that we can determine how much of it we can use in our final design for the Sun Room? 💭