How to extend a loft hatch without cutting through joists?

[nkailo]

Im looking to extend a hatch in a cutloft to accommodate a premade 60cm x 1meter hatch & ladder.
As you can see from the photo the existing size hatch is 60cm x 41cm. So the width is fine already 60cm- but to get 1m length would potentially need cutting through 2 joists as the distance betwween Joist 1 (J1) and Joist 2 (J2) is 41cm and the distance between J1 & J3 is 87.5cm.

So Is it ok to cut through the joists?
I presume this is a common problem as distances between joists are not that great?
If not how would the hatch be extended?

there are also tounge and groove boards fitted directly to the joists throughout the loft- these have been removed in this areafor the photo
Mnay thanks for your help in advance

 

[blup]

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[blup]

Im looking to extend a hatch in a cutloft to accommodate a premade 60cm x 1meter hatch & ladder.
As you can see from the photo the existing size hatch is 60cm x 41cm. So the width is fine already 60cm- but to get 1m length would potentially need cutting through 2 joists as the distance betwween Joist 1 (J1) and Joist 2 (J2) is 41cm and the distance between J1 & J3 is 87.5cm.

So Is it ok to cut through the joists?
I presume this is a common problem as distances between joists are not that great?
If not how would the hatch be extended?

there are also tounge and groove boards fitted directly to the joists throughout the loft- these have been removed in this areafor the photo
Mnay thanks for your help in advance

Joist 2 looks to have been put in purely for the existing loft door. Joist 1 may be offering structural support to the two upright struts/rafters in the top left of the pic.