If you are on the lookout for some big returns for your investment portfolio, then check out the two ASX 200 shares listed below.

That's because they have been named as buys by analysts and tipped to rise strongly over the next 12 months. Here's what sort of returns could be on the cards for buyers:

James Hardie Industries plc (ASX: JHX)

Bell Potter thinks that James Hardie could be an ASX 200 share to buy now.

The broker believes that the buildings materials company is well-placed for growth in the coming years thanks to a structural shift towards fibre cement in the United States. It also feels that significant share price weakness following news of a major acquisition has created an attractive buying opportunity. It explains:

In our view, JHX is poised for continued earnings expansion, driven by the structural shift towards fibre cement in the US. Households in the US continue to shift to fibre cement cladding from vinyl/timber, providing a multi-year runway for JHX's revenue and profit growth. With JHX announcing its intent to purchase AZEK, the share price has fallen from ~25%. While debate still wages around the deal, we retain JHX in our focus list as we see upside from these levels.

Bell Potter has a buy rating and $63.00 price target on its shares. This implies potential upside of 73% for investors over the next 12 months.

Northern Star Resources Ltd (ASX: NST)

Analysts at Macquarie think that this gold miner's shares could be cheap at current levels and have named it as an ASX 200 share to buy.

The broker highlights that the acquisition of De Grey Mining leaves it well-placed to grow its production over the remainder of the decade. It said:

We view the deal as accretive on production, reserves and NAV but also enhancing growth and 5-year NPV upgrade momentum. [..] NST's acquisition of DEG makes sense with Hemi accretive on production, reserves and NAV but also enhancing growth and 5-year NPV upgrade momentum. The project also looks set to dovetail nicely with the KCGM expansion and should drive NST to +2.5Mozpa by FY29.

Last week, the broker put an outperform rating and $27.00 price target on the company's shares. Based on its current share price of $20.84, this suggests that investors could get a 30% return on their investment between now and this time next year.