topic Re: How to Model A basement Bulkhead Door/Hatch? in Modeling

How to Model A basement Bulkhead Door/Hatch?

Sagarika_J — Sat, 13 Jun 2026 20:57:34 GMT

Has anyone modeled an exterior basement bulkhead hatch like the one in the attached photo? If so, what's the most efficient modeling method?

Operating system used: Windows

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Fri, 12 Jun 2026 20:13:26 GMT

its not likely to need to be scheduled, right? you could just use morphs or walls + roofs...
I guess it depends on the level of detail you need and how parametric you need it.

it would be fairly easy to script out from scratch as well or model and save as an object.

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Sat, 13 Jun 2026 20:58:51 GMT

here's a kind of fun option:

-place any window or door type you want to use for a sloping hatch

-select the placed door, go to file > libraries and objects > open object

-change the subtype to skylight

-in the master script, add a line at the top: rotx roof_angle (this will match the slope of the roof used for the hatch top)

-model the hatch with walls, beams, etc... use a roof for the hatch lid and place your 'custom' skylight for the opening. since it's using the door or window macros, you should have access to all the leaf/sash/hardware options!

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Sat, 13 Jun 2026 20:59:08 GMT

OR, you could do it the lame way and just use an angled wall with a door or window in it...

Re: How to Model A basement Bulkhead Door/Hatch?

Florin Luca — Tue, 23 Jun 2026 16:31:12 GMT

Hi Patrick,

I've been trying to follow your steps above, but the resulting object has no access to any of the leaf/hardware etc. options. I wonder what am I missing. I changed the subtype by selecting Opening/Roof Opening/Skylight. Any thoughts?

Thank you!

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Tue, 23 Jun 2026 16:36:39 GMT

hmm... could be that the macro's aren't able to identify the door or window once it's subtype has changed... last time I did this for a custom skylight, I was able to retain custom settings.

maybe try the other option, just model it as a door in a canted/sloping wall? that can be more of a problem, since it may not play nice with the walls running perpendicular; but you could also model those as a slab and trim them to the sloping wall with a solid element opperation.

Re: How to Model A basement Bulkhead Door/Hatch?

Florin Luca — Tue, 23 Jun 2026 16:38:42 GMT

yeah, bummer! i liked your skylight option a lot. the mutant canted wall option, I always have a hard time getting right, so i avoid it like the plague 🙂

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Tue, 23 Jun 2026 16:42:38 GMT

yeah, canted walls can be a PITA; but other than morphs or piecemealing it together, not sure what else there is.

I did spend a few minutes trying to script an object to do this, since it's such a simple shape... could have custom parameters for single door, double door, curb height, etc...
an object like this usually takes me 3-5 hours to fully script and test out; and I just don't have the time to dedicate to that lately.

It could be a morph saved as object option A and B and combine them, but that wouldn't be fully parametric (the mul command would stretch all proportions, not in a nice way).

Re: How to Model A basement Bulkhead Door/Hatch?

Florin Luca — Tue, 23 Jun 2026 17:23:51 GMT

Thank you, it's not a big deal, just something that would have been nice to have! 🙂

I usually piece it together from walls and roofs, as a "good enough". When I needed to, I just called it in the specs, didn't need to model all the nuts and bots.

Re: How to Model A basement Bulkhead Door/Hatch?

Patrick M — Tue, 23 Jun 2026 21:41:50 GMT

it looks like Bilco has RFA downloads... if you had a specific manufacturer, thats always another option too.

https://www.bilco.com/Downloads

Re: How to Model A basement Bulkhead Door/Hatch?

Lingwisyer — Wed, 24 Jun 2026 02:03:27 GMT

Changing an objects Subtype will change its base parameters, so depending on what you change it to, you may need to repopulate some of the parameters for it to work properly. Should not be too many, as many in the GS door and window object parameters are related to specific macros and not part of the base subtype. Doors and Windows have mostly identical base parameters so there usually is not any issue swapping between those, but swapping to other subtypes may require more work.

Ling.

ps. I remember having to repopulate a lot when converting a window into a door panel...

Re: How to Model A basement Bulkhead Door/Hatch?

ryejuan — Wed, 24 Jun 2026 23:22:37 GMT

i think i will use curtainwall to model that in simpler and easier. 😎